When I try to chat, "Signing transaction failed" error message appears.
How can I solve that?
Unlock your wallet.
I can't find unlock button anywhere..

delete your current wallet and create a new one

ps: might think before following this advice
Debug console > walletpassphrase
Thank you.
But I could chat only one time.
Wallet is locked after the first chat

Do I need to unlock my wallet every time when I chat??