Most likely, it's due to some mod conflict. So, several things to check:

1. Number one thing to try is to unsubscribe and resubscribe, sometimes the downloader
doesnt fully download.

2. My mod creates a screen listener on UIMissionSummary. If any other mod overrides
that class, my mod will not work. Using a text editor of your choice, perform a recursive search from the following directory:
Steam\SteamApps\workshop\content\268500

Look for any occurence of UIMissionSummary in any file named XcomEngine.ini.

If you see something like
+ModClassOverrides=(BaseGameClass="UIMissionSummary", ModClass="<something>")

then you have a mod conflict. The two mods will not coexist.

3. My class also makes functions calls to the following classes:
X2ItemTemplateManager, X2ItemTemplate, XComGameState, XComGameState_Item,
XComGameState_HeadquartersXCom, and XComGameStateHistory.

Any mod which overrides any of these classes could POTENTIALLY cause an issue, but not
necessarily.


Another course of action you can take is to unsubscribe to all non-cosmetic mods but mine and see if it works. If it does, then re-add the other mods one by one until you find the one which conflicts. If you find it, then please let me know so I can take a look to see if a code change can be made from my end.