OK. I found something interesting and (hopefully) the cure.
Let me repeat what
bugs features I have discovered in BAT JTW Multiplay.
When two home bases are created and aircraft and loadout limitations are enabled, the following
can happen when the mission is opened in Multiplay:
1. One base disappears.
2. The selection of aircraft types on one base is reduced. Sometimes, to just one.
3. Your selection of countries on one base is ignored. All countries appear in the "Airforce" drop list.
While trying to find the reason, I noticed that problems appear when certain loadouts are chosen for
some aircraft.
I tried to find and isolate the bug on the test map with two bases and just one a/c type Su-25 on both.
It was great fun. Many combinations, click-click-click... my head was spinning.
I managed to find "safe" loadouts for Su-25 but not the "bugged" ones.
A few cups of something later...
I was ready to give up when I became enlightened. I removed all loadouts from the "Selected loadouts" pane.
In other words:
FMB - select the Home base - View - Object - Aircraft - select the aircraft - Modify - Remove All.
Make sure that left pane Selected loadouts is
empty.
Save the mission. Go to Multiplay. No more bugs!
It was simple, stupid...but counter-intuitive for me since I had a habit of limiting loadouts.
I tried this method in the missions on other maps with several various a/c and it worked.
In a nutshell:
Do NOT select any loadouts in BAT JTW Multiplay. Leave it like that:
Yes, it complicates the player's choice since some aeroplanes have an insane choice of weaponry, dozens and even over 100. Yes, it makes some missions less interesting.
I'm afraid, it is what it is for the time being.
Footnote:
- I have a suspicion that there are many aircraft that are immune to this bug. Maybe those with a very short list of loadout, as An-26. Maybe some choppers.
- The safe loadouts for Su-25 were Default, Empty, first 4 lines after Default and the group starting with 4xKh-25MR.
- I tested JTW only. Maybe I'll try other eras later. "Two weeks, be sure".