Haven't seen that, the ME creates a new one each time I edit a mission, but the game doesn't. Apparently
[Text]
MissionBriefing=mission briefing
MissionTitle=mission title
isn't missed by the game itself, it already knows something called mission briefing must be the mission briefing.
Couple tips & tricks, for the random spawn groups I figured out an easy way to sort them - I never used a CHITOSE seaplane tender or a minesweeper in any of the set groups, so use one of those in random group 1 as the leader, the other in random group 2. Since nothing else entering Manila Bay has a minesweeper at career start, whatever time I see a minesweeper that must be random 2 arriving.
Another trick after screwing around with tedious numbers, instead of trying to calculate how much space I need between ships, just place a temporary sub then move the ships up to but not touching;
Sub is in the same position as the coordinates in the flotillas.upc file, space ships alongside, delete sub, and...
Your starting point in game doesn't need to be adjusted with trial and error.
