When enabling an extension my entire site breaks. This has happened on different sites I have built.
For this issue I was using fonts but I have had it crash on just checking the extension and hitting save.
In google chrome it says:
"HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request."
I don't believe there is anything wrong with my server configuration and I have tested this on a different server.
I can only fix this by reverting to a backup.