Exactly same here... Pulling my hair on this one, especially now as the WDC has increased in value over tenfold. Something just came up though, and would love to get some verification: On umtheenth time seeing the error code -14 (invalid passphrase) one of my password canditates started giving this: JSon RPC error! Connector: 'WDC'. Error: 'walletpassphrasechange <oldpassphrase> <newpassphrase>Changes the wallet passphrase from <oldpassphrase> to <newpassphrase>.'. Code: '-1' and I receive it by opening the encrypt wallet on WBC - 3.1.0 and typing my passphrace canditate as old password, new password twice as should ant finally pressing ok. nothing else. what does that mean? @Berzeck any help?
Found out about this recently, feeling interested and willing to contribute