Thank you for pointing it out aso118b.

In order to fully support atomic swaps, a non-hard fork upgrade is required. You may call it a soft-soft fork. The purpose is to allow what is considered a non-standard transaction from the PoV of the old nodes: Hash Time Lock Contract (HTLC).

No OP_Codes were added. I think there can be a lot of discussion on the different 'flavors' of forks--both hard fork and soft fork.

So ABSOLUTELY update your node to the latest release (1.1.0). That way all the nodes can support the newest feature. Also, make sure to include the updated node list in your yacoin.conf file.

With the said, the vast majority of nodes, and mining nodes have already been updated.

Also, I believe that YACoin is now the only other PoW coin besides Ethereum to have the ability to do a direct atomic swap with Bitcoin.