Prohibitory sign after updates
I have the dreaded prohibitory symbol after updating, and I have tried all of the ways suggested in the apple support pages. Every time I try a fix I end up with the same stop sign every time I boot back up.
You will see the prohibitory sign on all iWork '08 or iWork '09 applications because 32-bit applications are not supported on Catalina. Since you mention no application, or operating system version, the first sentence must be an assumption.