same happened for me today , I haven't opened bittrex in the last two weeks or so but tried to log in today to buy the CLAM dump
found this message that I need to contact support to enable my account , I have checked my email history there is no log in attempts at all since the last time I logged in also I have the basic verification so not sure why I can't enable my account
I missed a huge opportunity to trade CLAM due to this error . Contacted support and waiting for their reply

if there are some people here who had the similar issue and got an answer from support please share with us what exactly happened and why we have this error in the first place also what waiting time should I expect in order to get my account active again