A fix is already lined up for the next release, last I heard. You can try the following commands in console and try minting again afterwards:
rescanringctwallet
rescanblockchain
Another thing you can try is to send your CT amount to basecoin by using the console command sendstealthtobasecoin amount bv1xxxxx. Please note that this transaction will incur a small fee so please account for that when deciding on an amount (i.e. send 209.9 CT, leaving 0.1 CT for fees); adjust the amount as needed. You can then mint from basecoin with no worries.
If none of the above work, you may need to wait for the next release before you can move those funds. If there are any more solutions that you can try for this I will be sure to inform you. Again, we've very sorry for this.
rescanringctwallet
rescanblockchain
Another thing you can try is to send your CT amount to basecoin by using the console command sendstealthtobasecoin amount bv1xxxxx. Please note that this transaction will incur a small fee so please account for that when deciding on an amount (i.e. send 209.9 CT, leaving 0.1 CT for fees); adjust the amount as needed. You can then mint from basecoin with no worries.
If none of the above work, you may need to wait for the next release before you can move those funds. If there are any more solutions that you can try for this I will be sure to inform you. Again, we've very sorry for this.
12:34:34 sendstealthtobasecoin bv1q3yapmghzj8gpy2svtfttx6zmpgmfcqzmsht9xt 209.9
12:34:36 AddBlindedInputs failed: ringctwallet Dummy signature failed.. (code -4)
Your blockchain may have been corrupted and you will need to resync the wallet. To make this process faster, you're free to use one of the snapshots provided by the support team.
Thx.
However; be carefull, its a new exchange.