Trying to upgrade. I can open my wallet in Multibit classic without entering a password. I have never needed a password to open it and don't remember ever setting one up. I certainly have none recorded. But I can't export a key without entering a password. I tried sending the contents of the wallet to a new wallet in Multibit-HD but I don't know how much to send to allow for the transaction fee. There does not seem to be an "empty wallet" option.
2 Answers
MultiBit developer here. You should be able to simply spend from your Classic wallet into your new HD wallet. Don't try moving private keys around - that's really easy to get wrong and is one of the reasons we wrote HD in the first place.
There are full instructions on upgrading on the MultiBit website: https://multibit.org/en/help/hd0.1/how-to-upgrade-from-classic.html
Well I'm not totally sure about the password situation but you can easily send a 1 cent transaction fee and send the rest of your bitcoin to another wallet if that is an option. You don't even technically need a transaction fee it will just take much longer for the transaction to be confirmed if you do not send a fee.
1 cent currently is ~ 0.00004 BTC