Posting in EasyDiscuss gives no reaction but post is there -> leads to multiple posts and no stream entry is made

I made the update to 1.4.5 yesterday. I tested this on my backupsite and everything was working. Now there is a problem when I give an answer to an existing EasyDiscuss post. The post is posted but it is not shown, there is no reaction so it looks like the 'Submit' button got no effect though it does. Additionally the forum post does not create a stream entry.

Because of the missing reaction of the system my members made a LOT of duplicate posts because they thought it is not working.