Webkit encountered an internal error

Hello kudacat,

Thank you for posting to Apple Support Communities.

We understand you're having an issue with Safari.

A great troubleshooting step is to start the Mac us in safe mode to see if the issue occurs there. Here is how you can start up in safe mode: How to use safe mode on your Mac - Apple Support

Intel processor

1. Turn on or restart your Mac, then immediately press and hold the Shift key as your Mac starts up.

2. Release the key when you see the login window, then log in to your Mac. 

3. You might be asked to log in again. On either the first or second login window, you should see ”Safe Boot” in the upper-right corner of the window.

Safe mode prevents your Mac from loading certain software as it starts up, including login items, system extensions not required by macOS, and fonts not installed by macOS. It also does a basic check of your startup disk, similar to using First Aid in Disk Utility. And it deletes some system caches, including font caches and the kernel cache, which are automatically created again as needed.

Once you're in safe mode, see if the issue happens there.

If it is still happening, we recommend getting in touch with Apple Support for continued troubleshooting: Contact Apple Support

Take care.