dean970 wrote:
Thank you leroydouglas for your quick and precise answer!
I will keep this in mind for the next time when my favorites disappear from the Finder sidebar.
However, I'm not comfortable with a solution that requires deleting a system file or system preference file. I also do not know how to evaluate whether this "plist" is corrupt or not. Why should it be corrupt? Also, what is the guarantee for not doing a bigger harm by deleting this "plist" file?
I read on the forums that this issue isn't new to Mac OS users, so I would be very curious about Apple's official addressing on this matter. Or is it okay with Apple to have software glitches like this in their flagship laptop products?
Computers are nothing more than a accumulation of binary language, a CPU clock chip has only two states: On=1 and Off=0. Today's CPUs are capable of reading 4,000,000,000 1s and 0s per second or more...corruption happen, nothing new here...
The Finder plist is in your User account, this is not a System file as you indicate above. You do not have r/w privileges to System files...not since macOS Catalina...
ref: About the read-only system volume in macOS Catalina - Apple ..
https://support.apple.com/en-us/HT210650
As an alternative you can always erase your computer install a fresh copy of the macOS and set up your user count as new to replace the default Finder.plist in your user account.
ref: Erase and reinstall macOS - Apple Support - https://support.apple.com/guide/mac-help/erase-and-reinstall-macos-mh27903/mac
However, deleting the plist is much simpler, and will rebuild a default plist on reboot or relaunch of Finder—nothing new here either.
To trouble shoot further you can:
—Try a SafeBoot https://support.apple.com/en-us/HT201262
Takes noticeable longer to get to the login screen, does a 5 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc.
Login and test. Reboot as normal and test. Caches get rebuilt automatically.
In Safe mode third party system modifications and system accelerations are disabled, it removes malware, etc hampering smooth operation, however a reboot will put it back to normal mode.
This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.
—Test issue in another user (or guest user) account https://support.apple.com/guide/mac-help/set-up-other-users-on-your-mac-mtusr001/mac
This will tell you if it a universal issue or isolated to your user/admin account.
Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus
all known to cause issues on the macOS