Cannot enter in Admin Painel with boldial

Hello, I have a website done in boldial and a few days here I can not access the admin panel. Already picked out the theme and installed another and returned to normal. WordPress already updated and also updated the theme and the same thing happens. I tested on another server and is equal, no access panel. Just activate boldial I lose access to the panel.Appear the message:

“Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator to inform of the time the error occurred and of anything you might have done that may have caused the error.

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

Please, I really like this theme, what’s happening? thank you