That was the key. I had a modified file for MBot's dynamic campaigns in OvGME, but it only commented out the "os" and "io" lines, not the "lfs" line. Commented that one out too, and it worked like a charm. Got the notifications that the scripts loaded and saw the friendly tankers and AWACS. Didn't actually fly the mission so can't comment on whether there were enemies present, but I would wager everything works fine now.
Thanks for the help! :thumbup: