-snip-
My qt-wallet runs without problems. Are you using the current version 0.90.9.7? If not, update your wallet to the latest version and check if the wallet is running again. 
https://github.com/LIMXTEC/BitCore/releases/tag/0.90.9.7
It's not only the BTX wallet that is the problem, my whole collection of qt-wallets won't launch suddnely, all with the same error (so the version isn't the problem)
I had hoped someone had similiar issues before, and knew how to fix it, but I guess not..