... your wallet probably has a well known bug. The simplest fix is to install bread wallet on an iPhone or newer android phone, and use your multibit HD wallet seed words to create a new wallet in it. Afterwards all the addresses and balances from your multibit HD wallet will appear in bread wallet, and you can send your coins wherever you like.
According to dfevvbox bread wallet running on an iPhone can only use 12 word multibit HD wallet seed phrases.
Breadwallet won't work with 18 word on iOS it says seed should be 12 word
On the other hand, HCP says bread wallet running on an android can import both 12 and 18 word multibit HD wallet seed phrases.
I was honestly expecting it to say the same thing when I tried it on Android, but it worked perfectly with 18 words...
Unfortunately bread wallet won't install on older android phones, but HCP says "Simple Bitcoin Wallet" installs on them and that it can use MultiBit HD seeds.
...f you have an older Android device "Simple Bitcoin Wallet" also supports MultiBit HD seeds (tested with 12 and 18 word seeds).
If you can't use any of those solutions there are detailed instructions for using an offline webpage to extract the private keys from your MultiBit HD seed words at this link.
https://bitcointalksearch.org/topic/m.17773212
There are screenshots of the settings to use in that offline webpage at this link.
https://bitcointalksearch.org/topic/m.17819126
After you get your private keys you can install electrum and import them into it using the instructions here.
http://docs.electrum.org/en/latest/faq.html#can-i-import-private-keys-from-other-bitcoin-clients
