Martin,
Have you found out where "mx-agent was used”?
Many (all?) of our apps (running Mx 9.24.3) also show this error (once) on cloud environment after [re]starting app:
e.g.
2023-07-24T08:17:54.315827 [APP/PROC/WEB/0] INFO: Metrics are logged direct to metrics server.
2023-07-24T08:17:54.923242 [CELL/0] Container became healthy
2023-07-24T08:39:33.193905 [APP/PROC/WEB/0] WARNING - Core: Detected that mx-agent is used, which is deprecated. Use the Core.metrics() API instead.
2023-07-24T08:46:04.864176 [APP/PROC/WEB/0] WARNING - Core: Login FAILED: unknown user 'MxAdmin'.
e.g.
2023-07-21T07:47:59.366402 [CELL/0] Container became healthy
2023-07-21T07:55:24.050226 [APP/PROC/WEB/0] WARNING - Core: Detected that mx-agent is used, which is deprecated. Use the Core.metrics() API instead.
2023-07-21T07:55:24.808276 [APP/PROC/WEB/0] DEBUG - SAML_SSO: Start processing action (login/login) without SAMLResponse
I had the same issue with the mx.logger and found a topic where you have to change the logging so that you can see the widget that uses the particular action
If you set Client to Trace you might be able to find out which widget causes these messages.
Here you can see we are currently using the line widget, that uses a deprecated action.
I am unsure if this will also work when searching for the mx-agent
Hope this helps