One of our clients received one of these errors and alerted us on it:
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.
What was the issue? It was a change in the A RECORD IP address. Someone has access to their domain that did not know what they were doing and added another IP address to their website.
Websites need to be hosted on a server or servers somewhere in the “cloud” (aka datacenter). The location(s) of the server has an IP address. So pointing to the right IP address is important 🙂