Your Musicoin account does not count as a wallet. You need to set up a Musicoin wallet to transfer to before you transfer any coin to Cryptopia.
Where do i buy and sell Musicoin? How do I store them?
"Once you’ve bought Bitcoin, you can convert them into Musicoin at Bittrex and Cryptopia cryptocurrency exchange. Bittrex is recommended because of its higher liquidity. You can store your Musicoin either in your web wallet at musicoin.org or download a desktop wallet from our github page."
"Send musicoins to a friend or transfer to another wallet (desktop/geth client) for safe keeping.
Warning! Exchanges will not recognize coins sent directly from your profile."
You need to fully synchronise the wallet. I guess your computer clock is out of sync. So you need to do a NTP sync.
you should start over by renaming the Musicoin directory to oldMusicoin.
the you start the wallet but DO NOT import your key yet.
just click "open wallet" and wait till its full synced
then you import your key