Hi to all **My Mac: MacPro Catalina X.15.7 / MacBook Pro 2011** I'm looking for answers. For several weeks now, Firefox has been unable to start, and other programs are hindered upon launch. After shutting down, I have to start Firefox 130.x 2-3 times. The icon in the Dock doesn't respond, followed by a crash report. PDF Expert 2 also won't start unless Firefox has been started at least 2-3 times. After starting Firefox 2-3 times, it finally launches, as does PDF Expert 2. However, this can suddenly change again. As long as Firefox is trying to start, many NON-Mac programs, but also WINDOWS programs like Word & Co., are unable to start. And here's what I've tried: - Completely deleted all affected programs - Reinstalled Firefox - Deleted Word and Co. (!) (still not installed) - Reinstalled PDF Expert 2 - Reset PRAM, started Firefox without add-ons, booted Mac in safe mode... everything the internet suggests - The Activity Monitor shows no irregularities (how can I explore?) WHY is Firefox disrupting the entire Mac? What resources does the program use that causes other programs to be disrupted? What is affected that prevents multiple programs from starting? WHERE can I at least read about this (logs)? I have the same configurations on other Macs, and everything has been working fine for years, so it must be something with the MacBook Pro's system. Reinstall the entire system? I doubt it will fix the problems since everything runs fine without Firefox. Can anyone give me some clues? Thanks a lot.... I will give you more information, if any questions (if at all)