After some trouble today and some help from the community via Discord I've finally given up and decided to report it.
When you use a #include inside a Description.ext it works fine when testing locally MP on Windows, but when on Linux it's crashing the server.
When tested on locally MP it works fine.
#include from external source (Not inside mission folder) inside packed Mission pbo's is known to be broken since Eden. On Windows and Linux.
Also this is not a real crash. It just throws the fatal error "Include file not found" which needlessly kills the game instead of just failing to load the Mission.
Probably related to part of the PBO Header disappearing from Mission PBO's packed by Eden.
@dedmen But it works fine while doing it locally MP, not sure for Dedicated Windows though.
Also something that I've noticed while testing this, it looks like that all missions (Description.ext) are read when going to the host local screen. I got booted out of the game multiple times because I had missions with #include but didn't load the mods for them. Probably made like this if not it will be an other issue for sure.
Yeah that's intended. Because the description.ext can set the display Mission name via briefingName I think it needs to be parsed when the Mission's Name needs to be displayed.
You can also define a Picture to be shown in Mission selection so that's also a reason why it needs to be parsed.
Are you sure you are testing the PBO'ed mission in the MPMissions folder in local MP? Because if you load the unpacked Mission folder from your My Documents thingy then that Indeed works.
As I said only packed PBO's are influenced.
@dedmen Just tried it and yes I crashed when Testing it with the PBO Locally as well. So seems like its a overall issue.
I guess issue could be closed then if this is reported on a different issue.