Error all of a sudden

After using 2.2.2 for some time, all of a sudden I get errors on my blog. The frontpage is working, but when I want to click one of the articles it gives me the following error:

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

Please contact the server administrator, *** 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.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

I have not changed anything on the config or the database, but still it happens. My host is using phpsuexec.