Late in 2024, 2K removed its launcher and affected Midnight Suns' performance. Unfortunately, it's not all been good news.
Look on the Steam forum for XCOM 2 and you'll see threads noting that some mods no longer work, and having them installed can result in consistent crashing. Similar complaints have appeared on Reddit. Using the Alternative Mod Launcher, a community project that helped players get around the 2K launcher, doesn't help either.
Testing it myself, I found that XCOM 2 would only launch with certain mods enabled, and fail no matter which launcher I tried—both the old and new options provided by Steam and the Alternative Mod Launcher. The unifying factor seemed to be that mods with the War of the Chosen expansion as a hard requirement worked, while those without it did not. Mods like the Armory Camera Tweak, which prevents oversized characters from blocking the UI, were fine, while mods like the Imperial Guard Voice Pack, which lets you give your squaddies voice lines ripped from Dawn of War, did not.
I did find a fix for this, however. Go into the directory where Steam keeps your XCOM 2 mods, which should be Steam\steamapps\workshop\content\268500, and then open the subdirectory for any mods you've got installed. Each one will have a file that ends in ".XComMod" which can be opened with Notepad. If it doesn't have the line "RequiresXPACK=true" in there, add it at the end, then save. Do that for every mod you've ed, enable them in your mod launcher, and they should work. I've tried it with 40 different mods so far, from one that refreshes the reward deck when you enter the Avenger, to one that lets you outfit your soldiers in Sisters of Battle armor, and they seem to be working fine.
