an error occurred while processing this directive

I recently changed hosts. My new host reinstalled my site from a backup.

Since the migration, I have started getting this error.

{an error occurred while processing this directive}

I have gotten it at two different times.

One has been when I try to edit very old posts, like mostly Jan 2010. But not all the old posts produce the error, only some.

The other time was trying to edit my custom menu for Thesis. I was able to edit the menu, but when I pressed save, I received the error message.

I am not very swift at working on cPanel and files. If anyone has any ideas, I would to hear them.