Editing a UDT Permanently Changes Tag Quality to Unknown

I’ve been having a recurring problem across different gateways, servers and plants over the past few months; almost every time I edit a UDT (no matter how small the change), saving the changes will cause all tags in that UDT to change to Unknown quality permanently.

I’ve tried re-editing the UDT, deleting it and then re-importing it as an xml file, undoing my edit etc. but the only surefire way I’ve found that fixes it is to restart the OPC-UA module. This is obviously not ideal as it causes Ignition/PLC communication to temporarily go down across the entire plant.

Has anyone else encountered this problem or have any suggestions as to how to stop it happening? There doesn’t seem to be any reason or pattern behind it as far as I can tell.

The most recent occurrence was running version 7.9.5 but I’m fairly sure it’s happened on other 7.9 versions.


I have the similar issue, I’m using the ignition 7.8.5 with OPC-UA Ignition Server and Kepserver 5.19. I added a simple opc-tag, but the status is always unknown.