Hello LoobyfromLismore,
Welcome to Apple Support Communities!
If we understand your post correctly, your encountering an error message saying "WebKit encountered an internal error" (WebKitErrorDomain: 105) in Safari. We'd like to help with that.
This might also be related to Content Blockers that are specifically attached to Safari. Follow the steps in the article below.
If you can’t open a website in Safari on Mac
Make sure there are no configuration profiles installed that may control content: Use configuration profiles to standardize settings on Mac computers
Let us know if you have any questions.
Thank you for using Apple Support Communities.
Take care!