I'm having random error on my customized screen. It seems fine on few minutes, and then this pop-up shows.
It says "Unauthorized Request", I checked on the Trace Screen, It doesn't point where the error raises.
This was a bug in Acumatica. I would check with Acumatica as they provided a patch for us in the past. Not sure what version this might be fixed in. Some developers were able to get the errors, and others were not. The patch was a few updated dll and update to the web.config.
I cannot remember the exact details, but if it helps temporarily try to use a different browser or clear browser cache. I think that helped some people.
If not on the latest build for the version you are on, you can also try this. I think it was resolved near the end of June but not exactly sure.