lightroom classic crashes

If you have a ton of other programs or tabs open, close those so that your computer can focus on Lightroom. Then you can always check to see how much RAM your computer has, and how much is being used up. It may just be that your computer isn't fit to handle it. 

Also, sometimes it can help to optimize the lightroom catalog if it hasnt been optomized in a while. When you open Lightroom, click file -> Optomize Catalog... and let it do it's thing. 

Try resetting preferences, can't hurt, often helps:

https://helpx.adobe.com/lightroom-classic/help/setting-preferences-lightroom.html

Please tell us your OS, the exact version of Lightroom as well as some more about your hardware like GPU, CPU, RAM...

Try if it helps to reset preferences: https://www.lightroomqueen.com/how-do-i-reset-lightrooms-preferences/

Note that these are not reset by removing and reinstalling LR.

Moved from Using the Community (which is about the forums) to a better forum
To find a forum for your program please start at https://community.adobe.com/

Also, When you ask a question you need to provide some basic information
-Forum quick start https://community.adobe.com/t5/Community-Help/ASK-Forum-Success-Guide-Efficiently-using-the-forums/td-p/4791542
-https://community.adobe.com/t5/Get-Started/Questions-you-need-to-answer-to-receive-better-help/td-p/6199470
-https://community.adobe.com/t5/get-started/how-to-post-and-get-your-issue-resolved-or-what-do-you-need-to-know-to-solve-my-issue/td-p/11178657?page=1