Can't Test 10+ Players Map From Map Editor

[Antimatter101]

Around a month ago I downloaded the "fafmapeditor_alpha_v0703" map editor and have been using it, only to discover that I can't play-test some of the maps I've been working on.

The constraint seems to be that testing it with "File/Play map" only works properly if I'm trying to Test a map that has less than 10 players.

If I create a brand new map with 10 players, save it, and immediately try to test the map, then the "In Transit" loading screen enters some kind of infinite loop and never finishes.

I can delete Army_10 and it's spawn marker on that same map, save it, and then the test game loads fine afterwards. So somehow the infinite loop is caused by the 10th player.

I've tried getting a fresh copy of the map editor, but the problem persists.

Is this a known bug?
Is there something in particular I have to do to get 10+player maps to load properly?
Is there some other way I'm supposed to be able to test out how a map works than by using "File/Play map" ?

I've noticed that the test game generated with "File/Play map" doesn't work right (no UI overlay exists) if I've recently played a game on the FAF client with UI mods turned on.
In the past I've fixed that by turning off any mods before trying to use the Map Editor's map testing feature.

Is that also normal behavior for the map editor, or is it an indication that I've got something configured wrong somewhere which might also be causing this other issue?