This occurs pretty randomly. If you have an option to change your external IP, try to do that. I had this once and when I got my new IP later in the day everything was working normally. I know some who had their problem bypassed in that way too.
i have a idea Why you don't reset your windows, it may helped. Reset windows is making all setting set to default and helped Server side error to get well, but you may lost your data , and i recommended to you to backup your data before to do this