changeNotification Error on Logs


We are receiving a bunch of logs with changeNotification.

We don’t see any information about this Log on the user manual. The message seems to be around a change on the Tag structure which certainly hasn’t been any change.

Current Version: 8.0.14

I can provide more information regarding this issue if necessary. Thanks!

Did you manage to resolve this issue? I’m also receiving this error and can’t identify where the problem is.

Hi @foliveira,

Sorry for the late reply.

We have been able to reduce the number of errors in the log by eliminating UDTs that we were not using in any project. However we still have 5 to 8 errors in each log update.

Was it possible for you to see where yours come from?

Can you enable DEBUG for tags.execution.batch? It might help zero in on where this NPE is coming from.

Thanks @kcollins1. Where can I enable it?

You can enable it in the Logs section of the Gateway Status webpage:

You can then go back to that and reset the levels once you’ve collected what you need (so that way you don’t fill up your logs)…

Thank you. It does not provide additional information to the error.

How about tags.execution.batchoperations (DEBUG) too?


In my case I didn’t notice I had passed the tag limit configured in TIA Portal for the OPC UA server of my S7-1500. This is where my problem was. As soon as I changed the limit from 1000 to 5000 (10000 is the limit per subscription), all tags configured in the project immediately started to refresh. Just a newcomer error. This is the first time I’m using the integrated OPC UA of the S7-1500. Nevertheless, based on Siemens documentation, I think I’m abusing the S7-1511 capacity…

Here I have a screenshot of the logger. Is there any way to know to which source the structure change belongs or to which tags these notifications belong?