diff --git a/core/dict.class.inc.php b/core/dict.class.inc.php
index 6e9f9d386..66cec36c9 100644
--- a/core/dict.class.inc.php
+++ b/core/dict.class.inc.php
@@ -3,7 +3,7 @@
 //
 //   This file is part of iTop.
 //
-//   iTop is free software; you can redistribute it and/or modify	
+//   iTop is free software; you can redistribute it and/or modify
 //   it under the terms of the GNU Affero General Public License as published by
 //   the Free Software Foundation, either version 3 of the License, or
 //   (at your option) any later version.
@@ -116,33 +116,50 @@ class Dict
 	 * @return string
 	 */
 	public static function S($sStringCode, $sDefault = null, $bUserLanguageOnly = false)
+	{
+		$aInfo = self::GetLabelAndLangCode($sStringCode, $sDefault, $bUserLanguageOnly);
+		return $aInfo['label'];
+	}
+
+	/**
+	 * Returns a localised string from the dictonary with its associated lang code
+	 *
+	 * @param string $sStringCode The code identifying the dictionary entry
+	 * @param string $sDefault Default value if there is no match in the dictionary
+	 * @param bool $bUserLanguageOnly True to allow the use of the default language as a fallback, false otherwise
+	 *
+	 * @return array{
+	 *     lang: string, label: string
+	 * } with localized label string and used lang code
+	 */
+	private static function GetLabelAndLangCode($sStringCode, $sDefault = null, $bUserLanguageOnly = false)
 	{
 		// Attempt to find the string in the user language
 		//
 		$sLangCode = self::GetUserLanguage();
 		self::InitLangIfNeeded($sLangCode);
 
-		if (!array_key_exists($sLangCode, self::$m_aData))
+		if (! array_key_exists($sLangCode, self::$m_aData))
 		{
-			IssueLog::Warning("Cannot find $sLangCode in dictionnaries. default labels displayed");
+			IssueLog::Warning("Cannot find $sLangCode in all registered dictionaries.");
 			// It may happen, when something happens before the dictionaries get loaded
-			return $sStringCode;
+			return [ 'label' => $sStringCode, 'lang' => $sLangCode ];
 		}
 		$aCurrentDictionary = self::$m_aData[$sLangCode];
 		if (is_array($aCurrentDictionary) && array_key_exists($sStringCode, $aCurrentDictionary))
 		{
-			return $aCurrentDictionary[$sStringCode];
+			return [ 'label' => $aCurrentDictionary[$sStringCode], 'lang' => $sLangCode ];
 		}
 		if (!$bUserLanguageOnly)
 		{
 			// Attempt to find the string in the default language
 			//
 			self::InitLangIfNeeded(self::$m_sDefaultLanguage);
-			
+
 			$aDefaultDictionary = self::$m_aData[self::$m_sDefaultLanguage];
 			if (is_array($aDefaultDictionary) && array_key_exists($sStringCode, $aDefaultDictionary))
 			{
-				return $aDefaultDictionary[$sStringCode];
+				return [ 'label' => $aDefaultDictionary[$sStringCode], 'lang' => self::$m_sDefaultLanguage ];
 			}
 			// Attempt to find the string in english
 			//
@@ -151,17 +168,17 @@ class Dict
 			$aDefaultDictionary = self::$m_aData['EN US'];
 			if (is_array($aDefaultDictionary) && array_key_exists($sStringCode, $aDefaultDictionary))
 			{
-				return $aDefaultDictionary[$sStringCode];
+				return [ 'label' => $aDefaultDictionary[$sStringCode], 'lang' => 'EN US' ];
 			}
 		}
 		// Could not find the string...
 		//
 		if (is_null($sDefault))
 		{
-			return $sStringCode;
+			return [ 'label' => $sStringCode, 'lang' => null ];
 		}
 
-		return $sDefault;
+		return [ 'label' => $sDefault, 'lang' => null ];
 	}
 
 
@@ -177,19 +194,25 @@ class Dict
 	 */
 	public static function Format($sFormatCode /*, ... arguments ....*/)
 	{
-		$sLocalizedFormat = self::S($sFormatCode);
+		['label' => $sLocalizedFormat, 'lang' => $sLangCode] = self::GetLabelAndLangCode($sFormatCode);
+
 		$aArguments = func_get_args();
 		array_shift($aArguments);
-		
+
 		if ($sLocalizedFormat == $sFormatCode)
 		{
 			// Make sure the information will be displayed (ex: an error occuring before the dictionary gets loaded)
 			return $sFormatCode.' - '.implode(', ', $aArguments);
 		}
 
-		return vsprintf($sLocalizedFormat, $aArguments);
+		try{
+			return vsprintf($sLocalizedFormat, $aArguments);
+		} catch(\Throwable $e){
+			\IssueLog::Error("Cannot format dict key", null, ["sFormatCode" => $sFormatCode, "sLangCode" => $sLangCode, 'exception_msg' => $e->getMessage() ]);
+			return $sFormatCode.' - '.implode(', ', $aArguments);
+		}
 	}
-	
+
 	/**
 	 * Initialize a the entries for a given language (replaces the former Add() method)
 	 * @param string $sLanguageCode Code identifying the language i.e. 'FR-FR', 'EN-US'
@@ -199,7 +222,7 @@ class Dict
 	{
 		self::$m_aData[$sLanguageCode] = $aEntries;
 	}
-	
+
 	/**
 	 * Set the list of available languages
 	 * @param hash $aLanguagesList
@@ -260,7 +283,7 @@ class Dict
 		{
 			$sDictFile = APPROOT.'env-'.utils::GetCurrentEnvironment().'/dictionaries/'.str_replace(' ', '-', strtolower($sLangCode)).'.dict.php';
 			require_once($sDictFile);
-			
+
 			if (self::GetApcService()->function_exists('apc_store')
 				&& (self::$m_sApplicationPrefix !== null))
 			{
@@ -270,7 +293,7 @@ class Dict
 		}
 		return $bResult;
 	}
-	
+
 	/**
 	 * Enable caching (cached using APC)
 	 * @param string $sApplicationPrefix The prefix for uniquely identiying this iTop instance
@@ -313,14 +336,14 @@ class Dict
 			}
 		}
 	}
-	
+
 	public static function MakeStats($sLanguageCode, $sLanguageRef = 'EN US')
 	{
 		$aMissing = array(); // Strings missing for the target language
 		$aUnexpected = array(); // Strings defined for the target language, but not found in the reference dictionary
 		$aNotTranslated = array(); // Strings having the same value in both dictionaries
 		$aOK = array(); // Strings having different values in both dictionaries
-	
+
 		foreach (self::$m_aData[$sLanguageRef] as $sStringCode => $sValue)
 		{
 			if (!array_key_exists($sStringCode, self::$m_aData[$sLanguageCode]))
@@ -328,7 +351,7 @@ class Dict
 				$aMissing[$sStringCode] = $sValue;
 			}
 		}
-	
+
 		foreach (self::$m_aData[$sLanguageCode] as $sStringCode => $sValue)
 		{
 			if (!array_key_exists($sStringCode, self::$m_aData[$sLanguageRef]))
@@ -351,7 +374,7 @@ class Dict
 		}
 		return array($aMissing, $aUnexpected, $aNotTranslated, $aOK);
 	}
-	
+
 	public static function Dump()
 	{
 		MyHelpers::var_dump_html(self::$m_aData);
@@ -374,7 +397,7 @@ class Dict
 		// No need to actually load the strings since it's only used to know the list of languages
 		// at setup time !!
 	}
-	
+
 	/**
 	 * Export all the dictionary entries - of the given language - whose code matches the given prefix
 	 * missing entries in the current language will be replaced by entries in the default language
@@ -387,7 +410,7 @@ class Dict
 		self::InitLangIfNeeded(self::$m_sDefaultLanguage);
 		$aEntries = array();
 		$iLength = strlen($sStartingWith);
-		
+
 		// First prefill the array with entries from the default language
 		foreach(self::$m_aData[self::$m_sDefaultLanguage] as $sCode => $sEntry)
 		{
@@ -396,7 +419,7 @@ class Dict
 				$aEntries[$sCode] = $sEntry;
 			}
 		}
-		
+
 		// Now put (overwrite) the entries for the user language
 		foreach(self::$m_aData[self::GetUserLanguage()] as $sCode => $sEntry)
 		{
diff --git a/dictionaries/hu.dictionary.itop.core.php b/dictionaries/hu.dictionary.itop.core.php
index e9f49ccef..cc7117c3f 100755
--- a/dictionaries/hu.dictionary.itop.core.php
+++ b/dictionaries/hu.dictionary.itop.core.php
@@ -20,7 +20,7 @@
  * @license     http://opensource.org/licenses/AGPL-3.0
  */
 Dict::Add('HU HU', 'Hungarian', 'Magyar', array(
-	'Core:DeletedObjectLabel' => '%1s (deleted)~~',
+	'Core:DeletedObjectLabel' => '%1$s (deleted)~~',
 	'Core:DeletedObjectTip'   => 'The object has been deleted on %1$s (%2$s)~~',
 
 	'Core:UnknownObjectLabel' => 'Object not found (class: %1$s, id: %2$d)~~',
@@ -204,8 +204,8 @@ Operators:<br/>
 	'Core:FriendlyName-Description' => 'Friendly name~~',
 
 	'Core:AttributeTag' => 'Tags~~',
-	'Core:AttributeTag+' => '',
-	
+	'Core:AttributeTag+' => 'Tags~~',
+
 	'Core:Context=REST/JSON' => 'REST~~',
 	'Core:Context=Synchro' => 'Synchro~~',
 	'Core:Context=Setup' => 'Setup~~',
diff --git a/dictionaries/hu.dictionary.itop.ui.php b/dictionaries/hu.dictionary.itop.ui.php
index 819a9695e..31929884e 100755
--- a/dictionaries/hu.dictionary.itop.ui.php
+++ b/dictionaries/hu.dictionary.itop.ui.php
@@ -443,7 +443,7 @@ We hope you’ll enjoy this version as much as we enjoyed imagining and creating
 	'UI:Error:2ParametersMissing' => 'Hiba: a következő paramétereket meg kell adni ennél a műveletnél: %1$s és %2$s.',
 	'UI:Error:3ParametersMissing' => 'Hiba: a következő paramétereket meg kell adni ennél a műveletnél: %1$s, %2$s és %3$s.',
 	'UI:Error:4ParametersMissing' => 'Hiba: a következő paramétereket meg kell adni ennél a műveletnél: %1$s, %2$s, %3$s és %4$s.',
-	'UI:Error:IncorrectOQLQuery_Message' => 'Hiba: nem megfelelő OQL lekérdezés: %1$',
+	'UI:Error:IncorrectOQLQuery_Message' => 'Hiba: nem megfelelő OQL lekérdezés: %1$s',
 	'UI:Error:AnErrorOccuredWhileRunningTheQuery_Message' => 'Hiba történt a lekérdezs futtatása közben: %1$s',
 	'UI:Error:ObjectAlreadyUpdated' => 'Hiba: az objketum már korábban módosításra került.',
 	'UI:Error:ObjectCannotBeUpdated' => 'Hiba: az objektum nem frissíthető.',
@@ -1050,7 +1050,7 @@ Akció kiváltó okhoz rendelésekor kap egy sorszámot , amely meghatározza az
 	'UI:Deadline_LessThan1Min' => '< 1 perc',
 	'UI:Deadline_Minutes' => '%1$d perc',
 	'UI:Deadline_Hours_Minutes' => '%1$dóra %2$dperc',
-	'UI:Deadline_Days_Hours_Minutes' => '%1$nap %2$dóra %3$dperc',
+	'UI:Deadline_Days_Hours_Minutes' => '%1$dnap %2$dóra %3$dperc',
 	'UI:Help' => 'Segítség',
 	'UI:PasswordConfirm' => 'Jóváhagyás',
 	'UI:BeforeAdding_Class_ObjectsSaveThisObject' => '%1$s objektumok hozzáadása előtt mentse ezt az  objektumot',
diff --git a/dictionaries/ja.dictionary.itop.core.php b/dictionaries/ja.dictionary.itop.core.php
index c235ecf67..6526d0a2f 100644
--- a/dictionaries/ja.dictionary.itop.core.php
+++ b/dictionaries/ja.dictionary.itop.core.php
@@ -20,8 +20,8 @@
  * @licence	http://opensource.org/licenses/AGPL-3.0
  */
 Dict::Add('JA JP', 'Japanese', '日本語', array(
-	'Core:DeletedObjectLabel' => '%1s (削除されました)',
-	'Core:DeletedObjectTip'   => 'オブジェクトは削除されました %1$s (%2$s)',
+	'Core:DeletedObjectLabel' => '%1$s (削除されました)',
+	'Core:DeletedObjectTip' => 'オブジェクトは削除されました %1$s (%2$s)',
 
 	'Core:UnknownObjectLabel' => 'オブジェクトは見つかりません (クラス: %1$s, id: %2$d)',
 	'Core:UnknownObjectTip'   => 'オブジェクトは見つかりません。しばらく前に削除され、その後ログが削除されたかもしれません。',
@@ -205,7 +205,7 @@ Operators:<br/>
 
 	'Core:AttributeTag' => 'Tags~~',
 	'Core:AttributeTag+' => 'Tags~~',
-	
+
 	'Core:Context=REST/JSON' => 'REST~~',
 	'Core:Context=Synchro' => 'Synchro~~',
 	'Core:Context=Setup' => 'Setup~~',
diff --git a/dictionaries/ja.dictionary.itop.ui.php b/dictionaries/ja.dictionary.itop.ui.php
index 3c78e7d90..95dfbbf41 100644
--- a/dictionaries/ja.dictionary.itop.ui.php
+++ b/dictionaries/ja.dictionary.itop.ui.php
@@ -820,7 +820,7 @@ We hope you’ll enjoy this version as much as we enjoyed imagining and creating
 	'UI:Delete:ConfirmDeletionOf_Count_ObjectsOf_Class' => '%2$sクラスの%1$dオブジェクトの削除',
 	'UI:Delete:CannotDeleteBecause' => '削除できません: %1$s',
 	'UI:Delete:ShouldBeDeletedAtomaticallyButNotPossible' => '自動的に削除されるべきですが、出来ません。: %1$s',
-	'UI:Delete:MustBeDeletedManuallyButNotPossible' => '手動で削除されるべきですが、出来ません。: %1$',
+	'UI:Delete:MustBeDeletedManuallyButNotPossible' => '手動で削除されるべきですが、出来ません。: %1$s',
 	'UI:Delete:WillBeDeletedAutomatically' => '自動的に削除されます。',
 	'UI:Delete:MustBeDeletedManually' => '手動で削除されるべきです。',
 	'UI:Delete:CannotUpdateBecause_Issue' => '自動的に更新されるべきですが、しかし: %1$s',
@@ -1124,7 +1124,7 @@ We hope you’ll enjoy this version as much as we enjoyed imagining and creating
 	'Enum:Undefined' => '未定義',
 	'UI:DurationForm_Days_Hours_Minutes_Seconds' => '%1$s 日 %2$s 時 %3$s 分 %4$s 秒',
 	'UI:ModifyAllPageTitle' => '全てを修正',
-	'UI:Modify_N_ObjectsOf_Class' => 'クラス%2$Sの%1$dオブジェクトを修正',
+	'UI:Modify_N_ObjectsOf_Class' => 'クラス%2$sの%1$dオブジェクトを修正',
 	'UI:Modify_M_ObjectsOf_Class_OutOf_N' => 'クラス%2$sの%3$d中%1$dを修正',
 	'UI:Menu:ModifyAll' => '修正...',
 	'UI:Button:ModifyAll' => '全て修正',
@@ -1141,7 +1141,7 @@ We hope you’ll enjoy this version as much as we enjoyed imagining and creating
 	'UI:BulkModify_Count_DistinctValues' => '%1$d 個の個別の値:',
 	'UI:BulkModify:Value_Exists_N_Times' => '%1$s, %2$d 回存在',
 	'UI:BulkModify:N_MoreValues' => '%1$d 個以上の値...',
-	'UI:AttemptingToSetAReadOnlyAttribute_Name' => '読み込み専用フィールド %1$にセットしょうとしています。',
+	'UI:AttemptingToSetAReadOnlyAttribute_Name' => '読み込み専用フィールド %1$sにセットしょうとしています。',
 	'UI:FailedToApplyStimuli' => 'アクションは失敗しました。',
 	'UI:StimulusModify_N_ObjectsOf_Class' => '%1$s: クラス%3$sの%2$dオブジェクトを修正',
 	'UI:CaseLogTypeYourTextHere' => 'テキストを入力ください:',
diff --git a/dictionaries/ru.dictionary.itop.core.php b/dictionaries/ru.dictionary.itop.core.php
index 2e19f6ba7..e915cc99a 100644
--- a/dictionaries/ru.dictionary.itop.core.php
+++ b/dictionaries/ru.dictionary.itop.core.php
@@ -9,8 +9,8 @@
  *
  */
 Dict::Add('RU RU', 'Russian', 'Русский', array(
-	'Core:DeletedObjectLabel' => '%1ы (удален)',
-	'Core:DeletedObjectTip'   => 'Объект был удален %1$s (%2$s)',
+	'Core:DeletedObjectLabel' => '%1$sы (удален)',
+	'Core:DeletedObjectTip' => 'Объект был удален %1$s (%2$s)',
 
 	'Core:UnknownObjectLabel' => 'Объект не найден (class: %1$s, id: %2$d)',
 	'Core:UnknownObjectTip'   => 'Объект не удается найти. Возможно, он был удален некоторое время назад, и журнал с тех пор был очищен.',
@@ -193,8 +193,8 @@ Dict::Add('RU RU', 'Russian', 'Русский', array(
 	'Core:FriendlyName-Description' => 'Полное название',
 
 	'Core:AttributeTag' => 'Тег',
-	'Core:AttributeTag+' => '',
-	
+	'Core:AttributeTag+' => 'Тег',
+
 	'Core:Context=REST/JSON' => 'REST',
 	'Core:Context=Synchro' => 'Synchro',
 	'Core:Context=Setup' => 'Setup',
diff --git a/dictionaries/sk.dictionary.itop.ui.php b/dictionaries/sk.dictionary.itop.ui.php
index e7db57eee..ba14fc64a 100644
--- a/dictionaries/sk.dictionary.itop.ui.php
+++ b/dictionaries/sk.dictionary.itop.ui.php
@@ -430,7 +430,7 @@ We hope you’ll enjoy this version as much as we enjoyed imagining and creating
 	'UI:Error:MandatoryTemplateParameter_group_by' => 'Parameter group_by je povinný. Skontrolujte definíciu šablóny zobrazenia.',
 	'UI:Error:InvalidGroupByFields' => 'Neplatný zoznam polí pre skupinu podľa: "%1$s".',
 	'UI:Error:UnsupportedStyleOfBlock' => 'Chyba: nepodporovaný štýl bloku: "%1$s".',
-	'UI:Error:IncorrectLinkDefinition_LinkedClass_Class' => 'Nesprávna definícia spojenia : trieda objektov na manažovanie : %l$s nebol nájdený ako externý kľúč v triede %2$s',
+	'UI:Error:IncorrectLinkDefinition_LinkedClass_Class' => 'Nesprávna definícia spojenia : trieda objektov na manažovanie : %1$s nebol nájdený ako externý kľúč v triede %2$s',
 	'UI:Error:Object_Class_Id_NotFound' => 'Objekt: %1$s:%2$d nebol nájdený.',
 	'UI:Error:WizardCircularReferenceInDependencies' => 'Chyba: Cyklický odkaz v závislostiach medzi poliami, skontrolujte dátový model.',
 	'UI:Error:UploadedFileTooBig' => 'Nahraný súbor je príliš veľký. (Max povolená veľkosť je %1$s). Ak chcete zmeniť tento limit, obráťte sa na správcu ITOP . (Skontrolujte, PHP konfiguráciu pre upload_max_filesize a post_max_size na serveri).',
@@ -1275,7 +1275,7 @@ Keď sú priradené spúštačom, každej akcii je dané číslo "príkazu", šp
 	'UI:DashletGroupBy:Prop-GroupBy:DayOfMonth' => 'Deň v mesiaci pre %1$s',
 	'UI:DashletGroupBy:Prop-GroupBy:Select-Hour' => '%1$s (hodina)',
 	'UI:DashletGroupBy:Prop-GroupBy:Select-Month' => '%1$s (mesiac)',
-	'UI:DashletGroupBy:Prop-GroupBy:Select-DayOfWeek' => '%1$ (deň v týžni)',
+	'UI:DashletGroupBy:Prop-GroupBy:Select-DayOfWeek' => '%1$s (deň v týžni)',
 	'UI:DashletGroupBy:Prop-GroupBy:Select-DayOfMonth' => '%1$s (deň v mesiaci)',
 	'UI:DashletGroupBy:MissingGroupBy' => 'Prosím zvoľte pole na ktorom objekty budú zoskupené spolu',
 
diff --git a/dictionaries/tr.dictionary.itop.core.php b/dictionaries/tr.dictionary.itop.core.php
index afc159585..0f5275dfb 100644
--- a/dictionaries/tr.dictionary.itop.core.php
+++ b/dictionaries/tr.dictionary.itop.core.php
@@ -214,8 +214,8 @@ Operators:<br/>
 	'Core:FriendlyName-Description' => 'Yaygın Adı',
 
 	'Core:AttributeTag' => 'Tags~~',
-	'Core:AttributeTag+' => '',
-	
+	'Core:AttributeTag+' => 'Tags~~',
+
 	'Core:Context=REST/JSON' => 'REST~~',
 	'Core:Context=Synchro' => 'Synchro~~',
 	'Core:Context=Setup' => 'Setup~~',
@@ -324,7 +324,7 @@ Dict::Add('TR TR', 'Turkish', 'Türkçe', array(
 	'Change:AttName_SetTo_NewValue_PreviousValue_OldValue' => '%1$s\'nin değeri %2$s olarak atandı (önceki değer: %3$s)',
 	'Change:AttName_SetTo' => '%1$s\'nin değeri %2$s olarak atandı',
 	'Change:Text_AppendedTo_AttName' => '%2$s\'ye %1$s eklendi',
-	'Change:AttName_Changed_PreviousValue_OldValue' => '%1$\'nin değeri deiştirildi, önceki değer: %2$s',
+	'Change:AttName_Changed_PreviousValue_OldValue' => '%1$snin değeri deiştirildi, önceki değer: %2$s',
 	'Change:AttName_Changed' => '%1$s değiştirildi',
 	'Change:AttName_EntryAdded' => '%1$s değiştirilmiş, yeni giriş eklendi.',
 	'Change:State_Changed_NewValue_OldValue' => 'Changed from %2$s to %1$s~~',
diff --git a/tests/php-unit-tests/integration-tests/DictionariesConsistencyAfterSetupTest.php b/tests/php-unit-tests/integration-tests/DictionariesConsistencyAfterSetupTest.php
new file mode 100644
index 000000000..8b54282f6
--- /dev/null
+++ b/tests/php-unit-tests/integration-tests/DictionariesConsistencyAfterSetupTest.php
@@ -0,0 +1,242 @@
+<?php
+
+namespace Combodo\iTop\Test\UnitTest\Integration;
+
+use Combodo\iTop\Test\UnitTest\ItopTestCase;
+
+class DictionariesConsistencyAfterSetupTest extends ItopTestCase
+{
+	//used by testDictEntryValues
+	//to filter false positive broken traductions
+	private static $aLabelCodeNotToCheck = [
+		//use of Dict::S not Format
+		"UI:Audit:PercentageOk",
+
+		//unused dead labels
+		"Class:DatacenterDevice/Attribute:redundancy/count",
+		"Class:DatacenterDevice/Attribute:redundancy/disabled",
+		"Class:DatacenterDevice/Attribute:redundancy/percent",
+		"Class:TriggerOnThresholdReached/Attribute:threshold_index+"
+	];
+
+	public function FormatProvider(){
+		return [
+			'key does not exist in dictionnary' => [
+				'sTemplate' => null,
+				'sExpectedTraduction' => 'ITOP::DICT:FORMAT:BROKEN:KEY - 1',
+			],
+			'traduction that breaks expected nb of arguments' => [
+				'sTemplate' => 'toto %1$s titi %2$s',
+				'sExpectedTraduction' => 'ITOP::DICT:FORMAT:BROKEN:KEY - 1',
+			],
+			'traduction ok' => [
+				'sTemplate' => 'toto %1$s titi',
+				'sExpectedTraduction' => 'toto 1 titi',
+			],
+		];
+	}
+
+	/**
+	 * @param  $sTemplate : if null it will not create dict entry
+	 * @since 2.7.10 N°5491 - Inconsistent dictionary entries regarding arguments to pass to Dict::Format
+	 * @dataProvider FormatProvider
+	 */
+	public function testFormatWithOneArgumentAndCustomKey(?string $sTemplate, $sExpectedTranslation){
+		//tricky way to mock GetLabelAndLangCode behavior via connected user language
+		$sLangCode = \Dict::GetUserLanguage();
+		$aDictByLang = $this->GetNonPublicStaticProperty(\Dict::class, 'm_aData');
+		$sDictKey = 'ITOP::DICT:FORMAT:BROKEN:KEY';
+
+		if (! is_null($sTemplate)){
+			$aDictByLang[$sLangCode][$sDictKey] = $sTemplate;
+		}
+
+		$this->SetNonPublicStaticProperty(\Dict::class, 'm_aData', $aDictByLang);
+
+		$this->assertEquals($sExpectedTranslation, \Dict::Format($sDictKey, "1"));
+	}
+
+	//test works after setup (no annotation @beforesetup)
+	//even if it does not extend ItopDataTestCase
+	private function ReadDictKeys($sLangCode) : array {
+		\Dict::InitLangIfNeeded($sLangCode);
+
+		$aDictEntries = $this->GetNonPublicStaticProperty(\Dict::class, 'm_aData');
+		return $aDictEntries[$sLangCode];
+	}
+
+	/**
+	 * foreach dictionnary label map (key/value) it counts the number argument that should be passed to use Dict::Format
+	 * examples:
+	 *  for "gabu zomeu" label there are no args
+	 *  for "shadok %1 %2 %3" there are 3 args
+	 *
+	 * limitation: there is no validation check for "%3 itop %2 combodo" which seems unconsistent
+	 * @param $aDictEntry
+	 *
+	 * @return array
+	 */
+	private function GetKeyArgCountMap($aDictEntry) {
+		$aKeyArgsCount = [];
+		foreach ($aDictEntry as $sKey => $sValue){
+			$aKeyArgsCount[$sKey] = $this->countArg($sValue);
+		}
+		ksort($aKeyArgsCount);
+		return $aKeyArgsCount;
+	}
+
+	private function countArg($sLabel) {
+		$iMaxIndex = 0;
+		if (preg_match_all("/%(\d+)/", $sLabel, $aMatches)){
+			$aSubMatches = $aMatches[1];
+			if (is_array($aSubMatches)){
+				foreach ($aSubMatches as $aCurrentMatch){
+					$iIndex = $aCurrentMatch;
+					$iMaxIndex = ($iMaxIndex < $iIndex) ? $iIndex : $iMaxIndex;
+				}
+			}
+		} else if ((false !== strpos($sLabel, "%s"))
+			|| (false !== strpos($sLabel, "%d"))
+		){
+			$iMaxIndex = 1;
+		}
+
+		return $iMaxIndex;
+	}
+
+	/**
+	 * Warning: hardcoded list of languages
+	 * It is hard to have it dynamically via Dict::GetLanguages as for each lang Dict::Init should be called first
+	 **/
+	public function LangCodeProvider(){
+		return [
+			'cs' => [ 'CS CZ' ],
+			'da' => [ 'DA DA' ],
+			'de' => [ 'DE DE' ],
+			'en' => [ 'EN US' ],
+			'es' => [ 'ES CR' ],
+			'fr' => [ 'FR FR' ],
+			'hu' => [ 'HU HU' ],
+			'it' => [ 'IT IT' ],
+			'ja' => [ 'JA JP' ],
+			'nl' => [ 'NL NL' ],
+			'pt' => [ 'PT BR' ],
+			'ru' => [ 'RU RU' ],
+			'sk' => [ 'SK SK' ],
+			'tr' => [ 'TR TR' ],
+			'zh' => [ 'ZH CN' ],
+		];
+	}
+
+	/**
+	 * compare en and other dictionaries and check that for all labels there is the same number of arguments
+	 * if not Dict::Format could raise an exception for some languages. translation should be done again...
+	 * @dataProvider LangCodeProvider
+	 */
+	public function testDictEntryValues($sLanguageCodeToTest)
+	{
+		$sReferenceLangCode = 'EN US';
+		$aReferenceLangDictEntry = $this->ReadDictKeys($sReferenceLangCode);
+
+		$aDictEntry = $this->ReadDictKeys($sLanguageCodeToTest);
+
+
+		$aKeyArgsCountMap = [];
+		$aKeyArgsCountMap[$sReferenceLangCode] = $this->GetKeyArgCountMap($aReferenceLangDictEntry);
+		//$aKeyArgsCountMap[$sCode] = $this->GetKeyArgCountMap($aDictEntry);
+
+		//set user language
+		$this->SetNonPublicStaticProperty(\Dict::class, 'm_sCurrentLanguage', $sLanguageCodeToTest);
+
+		$aMismatchedKeys = [];
+
+		foreach ($aKeyArgsCountMap[$sReferenceLangCode] as $sKey => $iExpectedNbOfArgs){
+			if (in_array($sKey, self::$aLabelCodeNotToCheck)){
+				//false positive: do not test
+				continue;
+			}
+
+			if (array_key_exists($sKey, $aDictEntry)){
+				$aPlaceHolders = [];
+				for ($i=0; $i<$iExpectedNbOfArgs; $i++){
+					$aPlaceHolders[]=$i;
+				}
+
+				$sLabelTemplate = $aDictEntry[$sKey];
+				try{
+					vsprintf($sLabelTemplate, $aPlaceHolders);
+				} catch(\Throwable $e){
+					$sError = $e->getMessage();
+					if (array_key_exists($sError, $aMismatchedKeys)){
+						$aMismatchedKeys[$sError][$sKey] = $iExpectedNbOfArgs;
+					} else {
+						$aMismatchedKeys[$sError] = [$sKey => $iExpectedNbOfArgs];
+					}
+				}
+			}
+		}
+
+		$iCount = 0;
+		foreach ($aMismatchedKeys as $sError => $aKeys){
+			var_dump($sError);
+			foreach ($aKeys as $sKey => $iExpectedNbOfArgs) {
+				$iCount++;
+				if ($sReferenceLangCode === $sLanguageCodeToTest) {
+					var_dump([
+						'key label' => $sKey,
+						'expected nb of expected args' => $iExpectedNbOfArgs,
+						"key value in $sLanguageCodeToTest" => $aDictEntry[$sKey],
+					]);
+				} else {
+					var_dump([
+						'key label' => $sKey,
+						'expected nb of expected args' => $iExpectedNbOfArgs,
+						"key value in $sLanguageCodeToTest" => $aDictEntry[$sKey],
+						"key value in $sReferenceLangCode" => $aReferenceLangDictEntry[$sKey],
+					]);
+				}
+			}
+		}
+
+		$sErrorMsg = sprintf("%s broken propertie(s) on $sLanguageCodeToTest dictionaries! either change the dict value in $sLanguageCodeToTest or add it in ignored label list (cf aLabelCodeNotToCheck)", $iCount);
+		$this->assertEquals([], $aMismatchedKeys, $sErrorMsg);
+	}
+
+	public function VsprintfProvider(){
+		return [
+			'not enough args' => [
+				"sLabelTemplate" => "$1%s",
+				"aPlaceHolders" => [],
+			],
+			'exact nb of args' => [
+				"sLabelTemplate" => "$1%s",
+				"aPlaceHolders" => ["1"],
+			],
+			'too much args' => [
+				"sLabelTemplate" => "$1%s",
+				"aPlaceHolders" => ["1", "2"],
+			],
+			'\"% ok\" without args' => [
+				"sLabelTemplate" => "% ok",
+				"aPlaceHolders" => [],
+			],
+			'\"% ok $1%s\" without args' => [
+				"sLabelTemplate" => "% ok",
+				"aPlaceHolders" => ['1'],
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider VsprintfProvider
+	public function testVsprintf($sLabelTemplate, $aPlaceHolders){
+		try{
+			$this->markTestSkipped("usefull to check a specific PHP version behavior");
+			vsprintf($sLabelTemplate, $aPlaceHolders);
+			$this->assertTrue(true);
+		} catch(\Throwable $e) {
+			$this->assertTrue(false, "label \'" .  $sLabelTemplate . " failed with " . var_export($aPlaceHolders, true)  );
+		}
+	}
+	 */
+}
diff --git a/tests/php-unit-tests/src/BaseTestCase/ItopTestCase.php b/tests/php-unit-tests/src/BaseTestCase/ItopTestCase.php
index fc8cc58c3..7b77ab91a 100644
--- a/tests/php-unit-tests/src/BaseTestCase/ItopTestCase.php
+++ b/tests/php-unit-tests/src/BaseTestCase/ItopTestCase.php
@@ -277,6 +277,21 @@ abstract class ItopTestCase extends TestCase
 		return $method->invokeArgs($oObject, $aArgs);
 	}
 
+	/**
+	 * @param string $sClass
+	 * @param string $sProperty
+	 *
+	 * @return mixed property
+	 *
+	 * @throws \ReflectionException
+	 * @since 2.7.10 3.1.0
+	 */
+	public function GetNonPublicStaticProperty(string $sClass, string $sProperty)
+	{
+		$oProperty = $this->GetProperty($sClass, $sProperty);
+
+		return $oProperty->getValue();
+	}
 
 	/**
 	 * @param object $oObject
@@ -289,11 +304,27 @@ abstract class ItopTestCase extends TestCase
 	 */
 	public function GetNonPublicProperty(object $oObject, string $sProperty)
 	{
-		$class = new \ReflectionClass(get_class($oObject));
-		$property = $class->getProperty($sProperty);
-		$property->setAccessible(true);
+		$oProperty = $this->GetProperty(get_class($oObject), $sProperty);
 
-		return $property->getValue($oObject);
+		return $oProperty->getValue($oObject);
+	}
+
+	/**
+	 * @param string $sClass
+	 * @param string $sProperty
+	 *
+	 * @return \ReflectionProperty
+	 *
+	 * @throws \ReflectionException
+	 * @since 2.7.10 3.1.0
+	 */
+	private function GetProperty(string $sClass, string $sProperty)
+	{
+		$oClass = new \ReflectionClass($sClass);
+		$oProperty = $oClass->getProperty($sProperty);
+		$oProperty->setAccessible(true);
+
+		return $oProperty;
 	}
 
 	/**
@@ -306,11 +337,22 @@ abstract class ItopTestCase extends TestCase
 	 */
 	public function SetNonPublicProperty(object $oObject, string $sProperty, $value)
 	{
-		$class = new \ReflectionClass(get_class($oObject));
-		$property = $class->getProperty($sProperty);
-		$property->setAccessible(true);
+		$oProperty = $this->GetProperty(get_class($oObject), $sProperty);
+		$oProperty->setValue($oObject, $value);
+	}
 
-		$property->setValue($oObject, $value);
+	/**
+	 * @param string $sClass
+	 * @param string $sProperty
+	 * @param $value
+	 *
+	 * @throws \ReflectionException
+	 * @since 2.7.10 3.1.0
+	 */
+	public function SetNonPublicStaticProperty(string $sClass, string $sProperty, $value)
+	{
+		$oProperty = $this->GetProperty($sClass, $sProperty);
+		$oProperty->setValue($value);
 	}
 
 	public function RecurseRmdir($dir) {
@@ -383,4 +425,4 @@ abstract class ItopTestCase extends TestCase
 		}
 		closedir($dir);
 	}
-}
\ No newline at end of file
+}