diff --git a/application/cmdbabstract.class.inc.php b/application/cmdbabstract.class.inc.php
index 030e97db7..c23ec696a 100644
--- a/application/cmdbabstract.class.inc.php
+++ b/application/cmdbabstract.class.inc.php
@@ -3592,16 +3592,26 @@ EOF
 			$oPage->add_ready_script(InlineImage::EnableCKEditorImageUpload($this, $sTempId));
 		} else {
 			//we can directly apply the stimuli
+			$sExceptionMessage = null;
+			try {
 			$bApplyStimulus = $this->ApplyStimulus($sStimulus); // will write the object in the DB
-			if (!$bApplyStimulus) {
-				throw new ApplicationException(Dict::S('UI:FailedToApplyStimuli'));
-			} else {
+			}
+			catch (Exception $oException) {
+				// Catch any exception happening during the stimulus
+				$bApplyStimulus = false;
+				$sExceptionMessage =   ($oException instanceof CoreCannotSaveObjectException) ? $oException->getHtmlMessage() : $oException->getMessage();
+			}
+			finally {
 				if ($sOwnershipToken !== null) {
 					// Release the concurrent lock, if any
 					iTopOwnershipLock::ReleaseLock($sClass, $iKey, $sOwnershipToken);
 				}
-
-				return true;
+				if (!$bApplyStimulus) {
+					// Throw an application oriented exception if necessary
+					throw new ApplicationException($sExceptionMessage ?? Dict::S('UI:FailedToApplyStimuli'));
+				} else {
+					return true;
+				}
 			}
 		}
 
diff --git a/datamodels/2.x/itop-portal-base/portal/src/Form/ObjectFormManager.php b/datamodels/2.x/itop-portal-base/portal/src/Form/ObjectFormManager.php
index eb853ab24..07aedd49a 100644
--- a/datamodels/2.x/itop-portal-base/portal/src/Form/ObjectFormManager.php
+++ b/datamodels/2.x/itop-portal-base/portal/src/Form/ObjectFormManager.php
@@ -1222,9 +1222,18 @@ class ObjectFormManager extends FormManager
 				}
 			}
 		}
+		catch (CoreCannotSaveObjectException $e) {
+			$aData['valid'] = false;
+			$aData['messages']['error'] += array('_main' => array($e->getHtmlMessage()));
+			if (false === $bExceptionLogged) {
+				IssueLog::Error(__METHOD__.' at line '.__LINE__.' : '.$e->getMessage());
+			}
+		}
 		catch (Exception $e) {
 			$aData['valid'] = false;
-			$aData['messages']['error'] += array('_main' => array($e->getMessage()));
+			$aData['messages']['error'] += [
+				'_main' => [ ($e instanceof CoreCannotSaveObjectException) ? $e->getHtmlMessage() : $e->getMessage()]
+			];
 			if (false === $bExceptionLogged) {
 				IssueLog::Error(__METHOD__.' at line '.__LINE__.' : '.$e->getMessage());
 			}
diff --git a/datamodels/2.x/itop-portal-base/portal/src/Helper/ObjectFormHandlerHelper.php b/datamodels/2.x/itop-portal-base/portal/src/Helper/ObjectFormHandlerHelper.php
index 775ce7bb6..0bbbcc078 100644
--- a/datamodels/2.x/itop-portal-base/portal/src/Helper/ObjectFormHandlerHelper.php
+++ b/datamodels/2.x/itop-portal-base/portal/src/Helper/ObjectFormHandlerHelper.php
@@ -333,6 +333,8 @@ class ObjectFormHandlerHelper
 								'modal' => true,
 							);
 						}
+					} else {
+						throw new HttpException(Response::HTTP_INTERNAL_SERVER_ERROR, implode('<br/>', $aFormData['validation']['messages']['error']['_main']));
 					}
 					break;
 
diff --git a/pages/UI.php b/pages/UI.php
index 48660d198..aef1f3cd0 100644
--- a/pages/UI.php
+++ b/pages/UI.php
@@ -1206,8 +1206,16 @@ try
 					$bApplyTransition = $oObj->DisplayStimulusForm($oP, $sStimulus, $aPrefillFormParam);
 				}
 				catch (ApplicationException $e) {
+					$bApplyTransition = false;
 					$sMessage = $e->getMessage();
-					$sSeverity = 'info';
+					$sSeverity = 'warning';
+					ReloadAndDisplay($oP, $oObj, 'stimulus', $sMessage, $sSeverity);
+				}
+				catch (CoreCannotSaveObjectException $e) {
+					$bApplyTransition = false;
+					$aIssues = $e->getIssues();
+					$sMessage = $e->getHtmlMessage();
+					$sSeverity = 'warning';
 					ReloadAndDisplay($oP, $oObj, 'stimulus', $sMessage, $sSeverity);
 				}
 				if ($bApplyTransition) {