That message means that the sender created two transactions that attempted to spend the same coins. This is called "double spending" and is not allowed. One of the two transactions has to be marked as invalid by any Bitcoin node that sees the two. I believe most Bitcoin nodes will initially set aside whichever they received last. Over a short time time, the network as a whole comes to a common view about which transaction is accepted (so some nodes may change their decision after a few tens of minutes from their initial decision).
The transaction that you are looking at has long ago been determined, by all participants in the Bitcoin network, to be the incorrect one of the two.
How to fix the issue.
If you are the creator of the transaction, you should be able to find the other transaction where you spent that money.
If you are a recipient, you just treat that transaction as if it never happened, you were not paid.