Internal Server Error (500) when updating forum descriptions

[jayunsplanet]

When I go to update forum descriptions or forum permissions in my Admin Control panel and then click "SAVE" I get an Internal Server Error. I did not change anything or do anything fancy before this error occurred. It started a week ago. I will contact my host but I wanted to contact the people who might be able to diagnose the software that you know better than my host.

Thanks for any guidance/help you can provide.

See attached for screen shot

Error message...
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, support@supportwebsite.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.