diff --git a/SeedDMS_Core/Core/inc.ClassDocument.php b/SeedDMS_Core/Core/inc.ClassDocument.php
index b7ab3314b..398abfb0b 100644
--- a/SeedDMS_Core/Core/inc.ClassDocument.php
+++ b/SeedDMS_Core/Core/inc.ClassDocument.php
@@ -3404,7 +3404,7 @@ class SeedDMS_Core_DocumentContent extends SeedDMS_Core_Object { /* {{{ */
 		 */
 		if (!$ignorecurrentstatus && ($st["status"]==S_OBSOLETE || $st["status"]==S_REJECTED || $st["status"]==S_EXPIRED || $st["status"]==S_NEEDS_CORRECTION)) return $st['status'];
 
-		unset($this->_workflow); // force to be reloaded from DB
+		$this->_workflow = null; // force to be reloaded from DB
 		$hasworkflow =  $this->getWorkflow() ? true : false;
 
 		/* $pendingReview will be set when there are still open reviews */
@@ -6317,6 +6317,10 @@ class SeedDMS_Core_DocumentContent extends SeedDMS_Core_Object { /* {{{ */
 	 * $this->_workflow['parent']. $this->_workflow['id'] is the
 	 * id from table tblWorkflowDocumentContent which is used to
 	 * get log entries for this workflow.
+	 * This method will only get a currently running workflow in
+	 * a state. Once
+	 * workflow has ended, the current state of the workflow was
+	 * set to null.
 	 *
 	 * @return object/boolean an object of class SeedDMS_Core_Workflow
 	 *         or false in case of error, e.g. the version has not a workflow
@@ -6324,7 +6328,7 @@ class SeedDMS_Core_DocumentContent extends SeedDMS_Core_Object { /* {{{ */
 	function getWorkflow() { /* {{{ */
 		$db = $this->_document->getDMS()->getDB();
 
-		if (!isset($this->_workflow)) {
+		if (!$this->_workflow) {
 			$queryStr=
 				"SELECT a.`id` as `wdcid`, a.`parent`, b.* FROM `tblWorkflowDocumentContent` a LEFT JOIN `tblWorkflows` b ON a.`workflow` = b.`id` WHERE a.`version`='".$this->_version
 				."' AND a.`document` = '". $this->_document->getID() ."' "
@@ -6401,7 +6405,7 @@ class SeedDMS_Core_DocumentContent extends SeedDMS_Core_Object { /* {{{ */
 
 		$this->getWorkflow();
 
-		if (!isset($this->_workflow)) {
+		if (!$this->_workflow) {
 			return true;
 		}
 		$workflow = $this->_workflow['workflow'];
@@ -6444,7 +6448,7 @@ class SeedDMS_Core_DocumentContent extends SeedDMS_Core_Object { /* {{{ */
 
 		$this->getWorkflow();
 
-		if (!isset($this->_workflow)) {
+		if (!$this->_workflow) {
 			return true;
 		}
 
@@ -6568,7 +6572,7 @@ class SeedDMS_Core_DocumentContent extends SeedDMS_Core_Object { /* {{{ */
 		if(!$this->_workflow)
 			return false;
 
-		if (isset($this->_workflow)) {
+		if ($this->_workflow) {
 			$workflow = $this->_workflow['workflow'];
 			$db->startTransaction();
 
@@ -6580,7 +6584,7 @@ class SeedDMS_Core_DocumentContent extends SeedDMS_Core_Object { /* {{{ */
 
 			/* Calling getWorkflow() should find the parent workflow, better check */
 			$parent = $this->_workflow['parent'];
-			unset($this->_workflow);
+			$this->_workflow = null;
 			$this->getWorkflow();
 			if($this->_workflow['id'] != $parent) {
 				$db->rollbackTransaction();
diff --git a/SeedDMS_Core/package.xml b/SeedDMS_Core/package.xml
index b5f51db02..59887046a 100644
--- a/SeedDMS_Core/package.xml
+++ b/SeedDMS_Core/package.xml
@@ -12,7 +12,7 @@
   <email>uwe@steinmann.cx</email>
   <active>yes</active>
  </lead>
- <date>2021-12-11</date>
+ <date>2022-02-14</date>
  <time>13:44:55</time>
  <version>
   <release>6.0.18</release>
@@ -25,6 +25,7 @@
  <license uri="http://opensource.org/licenses/gpl-license">GPL License</license>
  <notes>
 - all changes from 5.1.25
+- replace all checks on isset(_workflow) by checking for null
  </notes>
  <contents>
   <dir baseinstalldir="SeedDMS" name="/">