Hi cmttat,
if you have correctly placed the two .txt log files in the Octane directory, you should see more verbose messages in the slave window and in the log window in the master.
To be able to save the log as a txt file to send it back to us, you have to copy the OctaneRender Standalone folder in another location than the Program folder where that is not write protected.
Another option could be that the issue comes from the Firewall

Have you already check this?
Wait a moment, 12 PC with at least 2 GPU gives 24 GPU...
Did you know that Octane has a limit of 20 GPU per master?
If you have more than 20 GPU, you have to set up two different masters with several specific slaves for each one.
ciao beppe