Mac Os Catalina update issue

Hey there, Bokhari2333.

Welcome to the Apple Support Communities! Thanks for posting your question about the troubles you're facing while attempting to update your Mac. We'd be glad to assist.

If you're running into an issue with updating, a great step to take would be trying the install in safe mode. Look over How to use safe mode on your Mac to learn how to launch into this special mode. If that doesn't take care of this for you, try completing the installation in a test user account. How to test an issue in another user account on your Mac will walk you through the set up process and how to launch into this new user account.

Let us know what you find out.

Take care.

Ensure that you have a current Time Machine backup, or Mojave drive clone (SuperDuper/Carbon Copy Cloner) before you even start. Get the free Go64 application and see what applications currently installed on Mojave are 32-bit, as these will not run on Catalina. You may also discover that your printer/scanner vendor does not support, or plan to support Catalina. Check before you leap. There is no Java 6 support in Catalina from Apple or any other source.

Catalina is an upgrade from Mojave, not an update. You must download and install Catalina from Software Update (or the Mac App Store). You cannot install a Catalina update/combo update for for an upgrade.

Hi Bokhari2333

have you try to download from Apple the combo update, and then launch as normal installation, usually combo updates work better than delta update...good luck!