MSG statements dying.

I have a small eithernet with 2 compacts 6 slc's and a 1400.
About a month ago we installed linx DDE server to generate production reports, production monitoring and downtime tracking. Also installed a couple clintes so the big wigs can sit and watch the line from there offices.

Over the last 2 weeks I have had 4 message statements in the compacts die. No matter what I did I could not get them to work. I finally had to create a new message tag and replace the MSG statement. It's like they had a finite number of uses and then just died.

Anybody ever seen anything like this? Any ideas on how to keep my messages from dying? Any help is greatly appreciated. Thanks to all the great guys in here that take time to help out. You are appreciated.

Were the messages completing with error codes and setting the /ER bit, or were they executed and just sitting there in the Enabled state ? If they were completing with errors, were you able to capture those error codes ?

The MSG statements just froze. They were eng but no dn or error. Just frozen. The en wouldnt even move go off when I made the rung false.