Index: lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/controller/AuthoringController.java
===================================================================
diff -u -r6132d98ee813109713fda3579007d4359596fc1e -r02a08907d878afbfefeb3a24c50c9981e69ad592
--- lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/controller/AuthoringController.java	(.../AuthoringController.java)	(revision 6132d98ee813109713fda3579007d4359596fc1e)
+++ lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/controller/AuthoringController.java	(.../AuthoringController.java)	(revision 02a08907d878afbfefeb3a24c50c9981e69ad592)
@@ -377,6 +377,7 @@
 	//validate form
 	MultiValueMap<String, String> errorMap = messageForm.validate(request, messageService);
 	if (!errorMap.isEmpty()) {
+	    messageForm.setTmpFileUploadId(FileUtil.generateTmpFileUploadId());
 	    request.setAttribute("errorMap", errorMap);
 	    return "jsps/authoring/message/create";
 	}
@@ -529,6 +530,7 @@
 	//validate form
 	MultiValueMap<String, String> errorMap = messageForm.validate(request, messageService);
 	if (!errorMap.isEmpty()) {
+	    messageForm.setTmpFileUploadId(FileUtil.generateTmpFileUploadId());
 	    request.setAttribute("errorMap", errorMap);
 	    return "jsps/authoring/message/edit";
 	}