Index: lams_tool_forum/conf/language/ApplicationResources.properties
===================================================================
diff -u -r27d386f3472e12afab03d53dfde3ed9b1c9a44d3 -r8538ea9651f478bd2973da6eda56176902fa92d7
--- lams_tool_forum/conf/language/ApplicationResources.properties	(.../ApplicationResources.properties)	(revision 27d386f3472e12afab03d53dfde3ed9b1c9a44d3)
+++ lams_tool_forum/conf/language/ApplicationResources.properties	(.../ApplicationResources.properties)	(revision 8538ea9651f478bd2973da6eda56176902fa92d7)
@@ -147,12 +147,13 @@
 button.release.mark=Release marks
 msg.mark.released=Marks in {0} have been released.
 label.authoring.advance.allow.upload=Allow learners to upload file
-label.authoring.advance.allow.new.topics=Allow Learners to create new topics
+label.authoring.advance.allow.new.topics=Allow learners to create new topics
 label.authoring.advance.number.reply=Number of posts per learner per topic 
 label.authoring.advance.minimum.reply=Minimum:
 label.authoring.advance.maximum.reply=Maximum:
 label.authoring.advance.no.minimum=No minimum
 label.authoring.advance.no.maximum=No maximum
 error.min.less.max=The maximum number of posts must be greater than or equal to the minimum number of posts.
 error.limit.char.less.zero=Limitation of input characters must be greater zero.
-error.less.mini.post=You must contribute at least {0} posts before finish.
\ No newline at end of file
+error.less.mini.post=You must contribute at least {0} posts before finish.
+error.must.have.topic=Please add at least 1 topic when "allow learners to create new topics" option is off.
\ No newline at end of file
Index: lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/actions/AuthoringAction.java
===================================================================
diff -u -rb56d90d0894b861844b15ebdb81a6587e7933e63 -r8538ea9651f478bd2973da6eda56176902fa92d7
--- lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/actions/AuthoringAction.java	(.../AuthoringAction.java)	(revision b56d90d0894b861844b15ebdb81a6587e7933e63)
+++ lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/web/actions/AuthoringAction.java	(.../AuthoringAction.java)	(revision 8538ea9651f478bd2973da6eda56176902fa92d7)
@@ -970,6 +970,13 @@
 				ActionMessage error = new ActionMessage("error.title.empty");
 				errors.add(ActionMessages.GLOBAL_MESSAGE, error);
 			}
+			if(!form.getForum().isAllowNewTopic()){
+				List topics = getTopicList(request);
+				if(topics.size() == 0){
+					ActionMessage error = new ActionMessage("error.must.have.topic");
+					errors.add(ActionMessages.GLOBAL_MESSAGE, error);
+				}
+			}
 			//define it later mode(TEACHER) skip below validation.
 			String modeStr = request.getParameter(AttributeNames.ATTR_MODE);
 			if(StringUtils.equals(modeStr, ToolAccessMode.TEACHER.toString())){