Okay it might be the terms I have used. The last 15 seconds after a user-session, when the system is preparing for full shutdown, there appears a list of small warnings, which I presume are to be given a notice if not full remedy.
I have been able to slowly tweak my system hardware into better performance when I pay attention to warnings, let alone full blown error messages.
The location of log files are sometimes very helpful. In addition, I have learned to run current script logs for user sessions to provide additional hints on warnings and other areas that should be attended to.
The most common one is: ...something like..iCCP warning: known incorrect sRGB profile...another refers to libGL.
But before I can react the system is already to shutdown.