MAC OS Catalina update error

I just had this exact same issue and booting in "Safe Mode" fixed the issue. I just went to Apple logo -> System Preferences -> Clicked on "Upgrade" to Catalina and the download resumed from being stuck for almost 48 hours. Thank you Apple Support!!!

-Koganinja

Greetings AnasAnuksa,

Thank you for using Apple Support Communities. It seems like there is trouble updating macOS. If there was a timed out error while installing, it could be a macOS issue. Are you able to update or install other apps?

How to update the software on your Mac

Use safe mode to isolate issues with your Mac

Please don't hesitate to let us know if the steps resolved your issue or if you need additional assistance.

Take care.