diff --git a/setup/itopdesignformat.class.inc.php b/setup/itopdesignformat.class.inc.php
index af7f89396..539d08632 100644
--- a/setup/itopdesignformat.class.inc.php
+++ b/setup/itopdesignformat.class.inc.php
@@ -898,7 +898,10 @@ class iTopDesignFormat
 		$oNodeList = $oXPath->query("/itop_design/classes//class/fields/field/values/value");
 		foreach ($oNodeList as $oNode) {
 			$sCode = $oNode->textContent;
-			$oNode->textContent = '';
+			// N°6562 textContent is readonly, see https://www.php.net/manual/en/class.domnode.php#95545
+//			$oNode->textContent = '';
+			// N°6562 to update text node content we must use the node methods !
+			$oNode->removeChild($oNode->firstChild);
 			$oCodeNode = $oNode->ownerDocument->createElement("code", $sCode);
 			$oNode->appendChild($oCodeNode);
 		}
@@ -988,7 +991,12 @@ class iTopDesignFormat
 				if ($oStyleNode) {
 					$this->DeleteNode($oStyleNode);
 				}
-				$oNode->textContent = $sCode;
+
+				// N°6562 textContent is readonly, see https://www.php.net/manual/en/class.domnode.php#95545
+//				$oNode->textContent = $sCode;
+				// N°6562 to update text node content we must use the node methods !
+				$oTextContentNode = new DOMText($sCode);
+				$oNode->appendChild($oTextContentNode);
 			}
 		}
 		// - Style
diff --git a/tests/php-unit-tests/unitary-tests/setup/iTopDesignFormat/iTopDesignFormatTest.php b/tests/php-unit-tests/unitary-tests/setup/iTopDesignFormat/iTopDesignFormatTest.php
index 83f6112a6..a68ab04ea 100644
--- a/tests/php-unit-tests/unitary-tests/setup/iTopDesignFormat/iTopDesignFormatTest.php
+++ b/tests/php-unit-tests/unitary-tests/setup/iTopDesignFormat/iTopDesignFormatTest.php
@@ -59,12 +59,6 @@ class iTopDesignFormatTest extends ItopTestCase
 		$sInputXml = $this->GetFileContent($sSamplesRelDirPath.$sXmlFileName.'.input');
 		$oInputDesignFormat = static::GetItopFormatFromString($sInputXml);
 
-		// N°6562 Disable test for 1.7 => 3.0 conversion on PHP 8.1.21 / 8.2.8 as it is failing due to unknown reason. Cause will be investigated next week.
-		if ((PHP_VERSION_ID === 80121 || PHP_VERSION_ID === 80208)
-			&& $oInputDesignFormat->GetVersion() === "1.7" && $sTargetVersion === "3.0") {
-			$this->markTestSkipped("Skip test for 1.7 => 3.0 conversion on PHP 8.1.21 as it is failing due to unknown reason. Cause will be investigated next week.");
-		}
-
 		$bResult = $oInputDesignFormat->Convert($sTargetVersion);
 		$aErrors = $oInputDesignFormat->GetErrors();
 		$this->assertCount($iExpectedErrors, $aErrors,
@@ -109,12 +103,6 @@ class iTopDesignFormatTest extends ItopTestCase
 		$oExpectedDesignFormat = static::GetItopFormatFromString($sExpectedXml);
 		$sExpectedVersion = $oExpectedDesignFormat->GetVersion();
 
-		// N°6562 Disable test for 1.7 => 3.0 conversion on PHP 8.1.21 / 8.2.8 as it is failing due to unknown reason. Cause will be investigated next week.
-		if ((PHP_VERSION_ID === 80121 || PHP_VERSION_ID === 80208)
-			&& $sInputVersion === "1.7" && $sExpectedVersion === "3.0") {
-			$this->markTestSkipped("Skip test for 1.7 => 3.0 conversion on PHP 8.1.21 as it is failing due to unknown reason. Cause will be investigated next week.");
-		}
-
 		if (version_compare($sInputVersion, $sExpectedVersion, '>=')) {
 			$this->markTestSkipped("This dataset correspond to a downward conversion ($sInputVersion to $sExpectedVersion) and we want to test upwards conversions => skipping !");
 		}