Index: lams_common/src/java/org/lamsfoundation/lams/util/FileUtil.java
===================================================================
diff -u -rbfad24196397ef8759dd17934284e5dfdbc45ff6 -rf3ef538574537ba41f51bef0335ee6df8495c987
--- lams_common/src/java/org/lamsfoundation/lams/util/FileUtil.java	(.../FileUtil.java)	(revision bfad24196397ef8759dd17934284e5dfdbc45ff6)
+++ lams_common/src/java/org/lamsfoundation/lams/util/FileUtil.java	(.../FileUtil.java)	(revision f3ef538574537ba41f51bef0335ee6df8495c987)
@@ -911,6 +911,9 @@
      * Gets upload dir for the given ID
      */
     public static File getTmpFileUploadDir(String tmpFileUploadId) {
+	if (StringUtils.isBlank(tmpFileUploadId)) {
+	    throw new IllegalArgumentException("File upload folder name must not be blank");
+	}
 	String uploadSubDir = FileUtil.prefix + tmpFileUploadId;
 	return new File(Configuration.get(ConfigurationKeys.LAMS_TEMP_DIR), uploadSubDir);
     }
Index: lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/controller/LearningController.java
===================================================================
diff -u -r6132d98ee813109713fda3579007d4359596fc1e -rf3ef538574537ba41f51bef0335ee6df8495c987
--- lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/controller/LearningController.java	(.../LearningController.java)	(revision 6132d98ee813109713fda3579007d4359596fc1e)
+++ lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/controller/LearningController.java	(.../LearningController.java)	(revision f3ef538574537ba41f51bef0335ee6df8495c987)
@@ -686,6 +686,8 @@
 		messageForm.getMessage().setSubject(reTitle);
 	    }
 	}
+	
+	messageForm.setTmpFileUploadId(FileUtil.generateTmpFileUploadId());
 
 	// Should we show the reflection or not? We shouldn't show it when the View Forum screen is accessed
 	// from the Monitoring Summary screen, but we should when accessed from the Learner Progress screen.