The mistake a system a file causes. The system windows be added 2 plus icons (right side). AmiBlitz3 these are out of order in that manner in a window than in Workbench. I cannot repair this unfortunately. Systemwise useful, would be harm to delete. But there is a solution! Delete/rename it System:S/AmigaSYSU-Startup file, and reboot. You disabled the program with this, in AmiBlitz3 will not be a mistake!