Lightroom Classic Freeze or Crashes.

Do you get any error message(s)? If yes post the message(s) word-by-word (or post an screenshot of the message).

First try to reset the preferences of Lightroom Classic:  How to reset Lightroom Classic preferences (adobe.com)

It's recommended to backup your preferences before you reset the preferences to the default settings: 

https://helpx.adobe.com/lightroom-classic/kb/preference-file-and-other-file-locations.html

Is your system up-to-date? Do you have installed all recent updates and patches for the operating system and the device drivers, especially the graphic driver. If you have a NVidia graphic card installed, make sure that you are using the recent Studio version of the driver, not the Game Ready version.

Please provide a copy of your 'System Info'. This can be get from the LrC Help > System Info menu item. There's a copy button in the System Info dialog. Press this button and paste the info into your next forum post.

Please make sure your GPU driver is up to date, and if you have an NVidia GPU, that it is a Studio driver and not a Game Ready driver.

Also, in LrC please go to Help->System Info and provide us the information there.