Ok now it has happened to my account. Bittrex asked for basic verification and then suggested that I go under the enhanced verification process. Happily I did to get it done. Then like some of you, I'm having the same problem. Something went wrong with processing of documents and the site told me to submit them again, but with no way to resubmit them.

I already emailed support. I expect its going to be long wait but I will post any progress in my experience so if it happens again to someone else, this thread will hopefully be helpful to them.