My entire balance in MultiBit HD appears as "unconfirmed". MultiBit HD does not allow me to send them to another address, so they are "stuck". When I click on the individual transactions under "Payments", the pop-up window says "Unknown transaction status". These transactions are more than a year old, and they seem to exist and be completely valid on blockchain.info (see for example this transaction.
I have already tried the "Repair wallet" option, but it has no effect. I have also tried using accelerators as described in this question but also without effect. Likewise this question is not helpful since it is about the generel speed of confirmations - my problem is related to MultiBit HD where my balance is unconfirmed even though the transations are confirmed on blockchain.info.
How can I get my bitcoins back?