@kknight Welcome to the Rockstor community.
From you picture it looks like you are running a non updated iso install 3.9.1-0. The testing channel has quite a few more fixes available but for replication you will need to be running a later version of the Stable channel which has very may more fixes in. Including some for the replication system as the testing channel is known to be broken for replication.
Not sure if your exact problem is this but given replication is known to be broken in the testing channel you will need to upgrade to stable channel on both machines for it to work at all. Sorry about that but it is the current ‘state of play’.
The stable channel is also now very much newer than the last released testing channel update. Please see the following thread’s intro for some background on this:
If you don’t fancy the stable channel release then for now at least you will have to forgo the replication feature. But in that case you will still have many benefits from running the last release of the testing channel as there were 16 fixes released on from what you are currently running and the last released testing (3.9.1-16) is equivalent to what would have been our nest stable release, ie 3.9.2-0. But we didn’t end up releasing a new iso (more details in that referenced thread)
Hope that helps.