Applications keeps crashing on Macos 11.3.1

Hello there, sidhvijaycg!

Thanks for reaching out to the Apple Support Communities! It sounds like you have issues with applications crashing on your Mac and not being able to shutdown or restart the Mac. First, we recommend taking a look at this article with steps to follow for How to use safe mode on your Mac. This will perform checks and stop certain software from starting up automatically. Once you are in safe mode, test to see if you have the same issue.

We also suggest following these steps to Set up users, guests, and groups on Mac and create a test user to see if the issue is user specific or system wide.

Let us know the results and have a terrific day!

Thanks for keeping us updated, sidhvijaycg!

Since the issue is not happening in safe mode, we suggest following the steps in the article How to use safe mode on your Mac, specificallly this section:

"If the issue doesn't continue in safe mode

If the issue doesn't continue while in safe mode, leave safe mode by restarting your Mac normally. Then test for the issue again. The issue might be resolved.

If the issue returns after leaving safe mode, startup items are probably at fault. Apps can install such items in numerous places, and they aren't always easy to find or recognize. For that reason, you should first make sure that you've installed any available updates for your Apple software and third-party apps.

If updating your software doesn't help, try any of these solutions:

• Test your login items.
• To learn whether software in your user account is causing the issue, set up a new user account, then log in to it and try to reproduce the issue in that account.
• Unplug all accessories from your Mac, including printers, drives, USB hubs, and other nonessential devices. You could have an issue with one or more of those devices or their cables.
• Reinstall macOS.

If you still need help, please contact Apple Support."

Take care!

Thanks for keeping us up to date!

If the issue is not happening in safe mode, are you able to copy the files while in safe mode? Check out this article to Use external storage devices with Mac.

Also, check out this link If you can’t move or copy an item on Mac.

Once that is done, you can follow the steps to Reinstall macOS.

Cheers!

sidhvijaycg wrote:

Want to Reinstall macOS but want to copy all my files to an external drive as a back up which I am not able to perform.

First of all, you need to have a Time Machine backup - full stop. Do not do ANYTHING until you have a backup.

Secondly, reinstalling the operating system will do nothing whatsoever. You would need to erase the hard drive and then reinstall the operating system. That will remove the 3rd party system modifications that are likely causing this problem.

There are some less destructive means of identifying which 3rd party system modifications are likely to be causing these problems. Alas, I have a vested interest in them so I'm not allowed to mention it here in the forums.