Photoshop 2021 (MAC) crashing when using brush tool

Hi, have you tried to reinstall the CC with this tool?

https://helpx.adobe.com/en/creative-cloud/kb/cc-cleaner-tool-installation-problems.html

Hi,

We're sorry about the trouble with Photoshop. Would you mind sharing the exact version of Photoshop you're using along with your computers macOS version? Did you start facing the issue after an update to Photoshop or to macOS?

You can try disabling the option to Use graphics Processor from Photoshop by going to Preferences, then Performance. Once done, quit & relaunch Photoshop to check if it helps. You can also try resetting the Brush tool using the steps suggested here: https://helpx.adobe.com/photoshop/kb/basic-troubleshooting.html#tool

If the issue persists, please try resetting the preferences of Photoshop using the steps mentioned here: https://adobe.ly/2Qzc0K3

Please backup your settings prior to resetting the preferences. You can check: https://adobe.ly/2vNz6FG

Let us know how it goes!

Regards,

Nikunj