Phpmyadmin error 500 - can't load anything

Question

I was trying to do a right join of two tables, but it seems like it was too much information or the syntax was wrong and then the page froze so I closed out of it. But when I tried to reload PHPmyadmin, it shows everything in red and nothing will load. I tried restarting the server but it's the same.

Is there anyway to reset it or something? Websites still load/access the database fine, it's just phpmyadmin seems to be blocked now?

It says

Cannot use a scalar value as an array
Error in processing request
Error code: 500
Error text: Internal Server Error (rejected)
It seems that the connection to server has been lost.
Please check your network connectivity and server status.

Thanks for any help