[Resolved] One member Getting internal server error.

[SpeedwayFreaks]

I am having a heck of a time finding an answer to this one.

I have one member who was creating a post and when he clicked on "Preview Post" he got the following error message:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, webmaster@xxxxx.com 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.

Now when he tries to create a "Post New Thread" he gets the same error, however, he can reply to a current thread no problem.

I had him create a new account to test with and he had no issues with the new account.

I was unable to get to the error logs in time to try and track it as he waited a few days to contact us. I have contacted our host thinking possibly that he may have triggered something in mod-sec but they were unable to locate anything as well.

We are currently running 4.2 PL3 and he is the only member this is happening to. Any direction on this issue would be greatly appreciated.

Thank you for your time.