My C5 page will not let me add any blocks...I can edit or delete them as I like, but cannot add any and am getting the message:

an unexpected error occurred
An error occurred while processing this request.


I also cannot make a backup of my database and get an Internal Server Error 500 trying to do so.

I can live without the database, but not being able to add blocks is a problem.

I am running on 5.6.3.4 which is as high as I can go with the theme we are running and don't really want to change the theme...especially not at this moment.

PLEASE HELP!