Perhaps the most confusing WordPress error that a beginner may come across is “Internal Server Error”, or sometimes “500 Internal Server Error”.
This error usually appears when there is something wrong, but the server is unable to identify where the problem is. Since the error message does not indicate where you should look for the error, it is pretty much up to you to figure this out.
We have compiled a list of solutions that you can try and one of them will help you resolve it. See how to fix internal server error in WordPress.