If I view the .sga file in the archive viewer, I can see that my objectives scar file is not included for some reason. I imagine due to "export packages" in world builder overwriting it. Without the objectives scar file in my .sga, I am unable to import it with my main scar file. Not 100% sure how to add my missing scar files to the .sga for the main scar file to import.
You can open .sga files with for example notepad or notepad++ and there at the top of the main SCAR file you import the other SCAR files (example: import("City_Centre_2_obj_FirstObjective.scar")).
I've seen that you can create a scenario pack in Mod Builder and manually add in the files, however, I am running into errors doing it that way as well.
I see the following error with my mod in the warnings file:
MOD -- Error loading mod pack 'C:\Users\Jace\Documents\My Games\Company of Heroes 2\mods\scenarios\CityCentre.sga': invalid file structure.
The problem is exactly what the error says. I would have to see how do you have your files structured to be able to help you.
Also, when I try to build my mod I get the following error:
C:\Program Files (x86)\Steam\steamapps\common\Company of Heroes 2\Archive.exe failed with exit code 2.
Error copying C:\Users\Jace\Documents\My Games\Company of Heroes 2\mods\scenarios\City_Centre_2.sga: The process cannot access the file 'C:\Users\Jace\Documents\My Games\Company of Heroes 2\mods\scenarios\City_Centre_2.sga' because it is being used by another process.
"because it is being used by another process" this means your CoH2 was running while you tried to build the mod.