How do I unlock the wallet?
To unlock the wallet you should do the following:
Go to menu Help - Debug Window - Console
Enter the following text:
walletpassphrase XXXXXXXXXXXXXX 60
walletpassphrase - a command
XXXXXXXXXXXXXX - your passphrase
60 - time in seconds to unlock the wallet for
If you entered the command correctly, you will see the wallet’s response null and will be granted access to work.
If you do not remember the passphrase you can try to unlock the wallet by importing the private key.
Note: you need to have the private key, which was created before the encryption (if the wallet is encrypted it would not allow you to generate private keys).