I've posted this in a couple of the other forums. It may be an old issue that everyone's already aware of but I couldn't find any similar postings on this issue so this is my solution for what it's worth.
First off let me stress that this is NOT a static.ini problem so shouldn't be seen as a solution for that type of problem. There are posts regarding using static.ini checker which should be consulted in that particular case. The problem described below may in fact be unique to our particular set up but again, perhaps others have similar problems and if this helps then great.
OK, a bit of background to understand the issue...
I created from scratch a US Fighter campaign for DCG using the Western Front Generic map and HSFX. I am not a DCG expert so we have been adjusting/tweaking the campaign as our little group progresses. Overall, the campaign itself works and is progressing fairly well.
THE PROBLEM: After generating a mission for the campaign in DCG we wanted to check a couple of things "on the ground" but could not get it to open in FMB. The map would appear with various aircraft flight paths and the little pop up window stating "Mission Loading". The mission would NOT completely load however. The little pop up would just sit there. None of the other objects (e.g. static, vehicles, Triggers) would appear. Not wanting to compromise the originally generated mission we would simply close out FMB and leave it alone.
THE SOLUTION: I was fairly confident that the static.ini was good because we were all using the same version of HSFX with no "external" additional mods that hadn't come with HSFX so all the objects etc should be good to go. I was convinced that the problem was related to something else.
So I did some digging on my own using Notepad by looking at the .mis files that were being generated to see if there were any anomalies in the actual text lines.
After scanning the text of the .mis file in Notepad I noticed that, for whatever bizarre reason, DCG had stuck a Static entry in the middle of the flight path coordinates of a flight, almost always in the Landing line. e.g. there would be "Static_103" stuck arbitrarily in one of the flight path lines. It would always be after the map grid coordinates data and before the other data in the line. I know where a ground target entry should be in the flightpath coordinates and eliminated that aspect. I have no idea why this happens but have assumed it's DCG vs a non-stock version of IL2 when it's calculating the data for a mission.
I understand the syntax required by the flightpath lines in the .mis file so I knew what part of the line I could safely delete.
So I cleaned up the .mis file checked again with FMB but no joy. Still not loading completely in FMB. WTH?? So back to the .mis file and after careful scanning of the lines again I discovered a not-so-obvious error in that DCG had inserted a couple of incorrect &0 entries. There were a couple of lines in the flightpaths that had a &0 immediately followed by a &1. I noticed that in older .mis files there is only ever one incident of the & per line, it is either a &1 or a &0, not both. Sooooo.......I did a search for all "&0 &1" and replaced with "&1" only and bingo, the mission loads normally in FMB
Again, this could be unique to our specific scratch-built campaign but if it happened to us it might happen to someone else so I'm tossing this solution out there and hopefully it will provide a BINGO moment for someone who is pulling their hair out with a similar issue.
If someone knows why DCG does this, I'd be curious as to the explanation and if there's already a known workaround.
P.S. Even without the solution mentioned here, the problematic missions will still work with no problem at all (i.e. our group can fly them with no issues). It's only accessing via FMB that is prevented by these "typos".