It seems it is not a technical issue, but some automatic account lock-up when you receive the "Currency operations not available" error. I have received it too without any details and I cannot withdrawl nor trade.
I have already submitted these 2 tickets: #251169 and #251893 but still have not received any reply nor any fix.
What can I do to get a fix to this?
There is no fix until the team there fixes it. I have the same issue. I never had problems before with htbtc but now only deposits work.