I encounter a problem.
Everytime i try to sent coins I get this error.
I tried
with coin control, without coin control
small amounts, big amounts
several addresses..
But getting the same error time after time?
Please let me know the error. If this is from the qt wallet, you may have an input in the wallet that is not correct. Try running the qt wallet with the rescan option. If you sent a transaction with the old qt but it never confirmed then again the wallet itself may not know the inputs. If that is the case copy/backup your wallet.dat and reinstall the qt wallet and resynchronize with the new qt wallet. Also make sure you have no addresses in your wallet with a lowercase "b". If you do let me know.