“The offer with offer ID ‘xxxxx’ has an invalid maker fee transaction.
The output of the maker fee tx is already spent.
You have to remove that offer to avoid failed trades.
If this happened because of a bug please contact the Bisq developers and you can request reimbursement for the lost maker fee.”
Any way to avoid???
Hi thanks for the message. Trades fail for a number of reasons.
In the above example it failed but to the output utxos already being spent. If you were the taker then it was a problem with the maker. If you were making the offer it might be a problem on your end.
Where you the maker or taker?
There is no way to avoid this, as far as it’s known, otherwise the fix would be on the way 
This guide could help you to understand what happened on your case, and how to proceed: Failed trades and deposit tx not confirmed troubleshoot (v1.5.4)
I was maker. I do not think a trade was started. I only listed.
Perhaps a warning message should be made to make a backup AFTER each listing.