Internal Server Error – Additionally, a 404 Not Found error was encountered whil

Hi there,

I get this error when using the subcription-button in my sidebar widget:

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 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

The configuration is completed and emails could be sent from wordpress as well as from the newsletter plugin.

I set the log level to “Debug” and the only content in the logfile that belongs to this error is:

12-09-2013 15:54:35 – DEBUG – 22870292 – Replace start
12-09-2013 15:54:35 – DEBUG – 22871748 – Replace end

Any idea how to fix this?

Thanks in advance!