System is busy

Hello,

have installed Profitori at our stage and get always the message “System is busy – please wait then try again”.
We can not switch from one area to an other one directly.
Means if you are in settings and want to go to reports, the above message pops up.
Going from settings to e.g. plugins and switch then to reports, it works.
But then, inside e.g. reports when click on Run, the same message appears.

Not sure what is causing this issue as site runs w/o any failures or issues.

Reagrds,
Hermann