Ron,
Thank you for your reply.
All plugin edits and files are present on my new Gaming and old Automation live multi-sites, I just can't "network activate" the Domain Mapping plugin on either.
When I do, the Dashboard page tries to refresh for awhile and then times out.
The issue also occurs when no other plugins are active and using a default wordpress theme.
That said, domain mapping is working on both currently. For instance, http://bandofgamers.net/ and http://casualadultgamers.com/ are both sub sites on a multisite setup and the domains do map right to the sub-sites.
Also of note, I've created two new multi-sites and on those there was no issue activating the plugin.
However, on one of the new sites, after I had imported everything successfully, and repointed the domains to that site, I lost the ability to access the dashboard with plugin activated so resorted to deactivating the plugin and editing the MySQL table manually to get it to work.
At this point, with both sites seemingly working, I'm going to take a break from troubleshooting the activating of the plugin to reflect on what might stop the plugin from activating.
The two sites in question do have a few other plugins in common, like Akismet, Jetpack, Yoast SEO and Regen Thumbnails, etc so maybe there is a conflict with one of those?
I do still have a new working site to experiment with, but at this point I need to get some work done to get paid so it will have to wait until some free time opens up.
I'll also note again that I'm pretty confused as to how the domain mapping works without the plugin being activated in the dashboard?
My only guess is that the edits and files being present are all that's needed to make it work, and that activating the WordPress plugin only provides a dashboard interface to allow editing of the domain mapping table.
Well that's it for me for now - my sincere thanks to you for your replies,
Shawn Tierney