Export private key from MultiBit without password - this is important.Then edit file with some editor like Notepad++ and copy only key - this is row without # ,and you must copy only key - no date and another symbols , and then in BitCoin-Qt open from Help->Debug window ->Console then type
importprivkey [label] [rescan=true]
without <>
where label is name of owner - your name.
I also am trying to import a Multibit key into Bitcoin-Qt. I can view the unencrypted key in Notepad, but I'm uncertain just how much of the text I'm to copy - is it everything in between the two # symbols? I have two wallets, and there appear to be two keys in between the # symbols. Would I be interpreting that right?
Also, my labels aren't owner name, they are descriptive - but when I try to import the key using the descriptive label, I get this error:
Error: value is type int, expected bool
If I try to import the key without any label, I get this error:
Error: Error parsing JSON:[rescan=true]