This is sadly a common issue due to the nature of the launcher, it can sometimes corrupt clean files you are using, and/or download them wrong etc. etc.

To avoid it, you should first use the custom mod manager (Kaedrin's mod manager). It will allow you to see your mods in order easier. Follow the instructions and succesfully setup the K.'s mod manager, open it, sort your mods by name (it is important, the mod on the top of the list should be sorted alphabetically in order to make them work, mods with punctuations, numbers etc. Should be on top and others will be sorted from a to z).

Then, start from the top of the list and slowly check all of their images if they are normal, or seen as an orange danger sign(in K.'s mod manager, when you click on a mod's name, the launcher lets u see the image of the mod too). A normal images means the files aren't corrupted (or the problem with it won't make your game crash, I'll talk about it later). Detect all of the corrupted mods with orange danger signs, unsub them, THEN delete the files of those mods from warhammer 2 data AND steamapps-workshop. To find them easier, note the mods name from K.'s mod manager, it will allow you to see the full name of the mod's file.

After succesfully deleting the mod, subs. it again, and check it if it's working or not. Note that, u should to this whenever ur game starts crashing. For example, I played 3 hours, shut downed my pc, opened it after 3-4 hours, and some files were corrupted. That happens because wh launcher got confused and corrupted some files because, A) a mod you are using updated , B) You uploaded a mod, or updated an existing one, or C) Wh launcher wanted to corrupt some files randomly(which is very rare, and it happens probably because some confusing shenanigans, which even the devs. can't fixing. Anyways, review all your mods with Kaedrin's mod manager, and regularly keep doing it whenever ur game crashes.

There is only one more small issue, which I mentioned before. Even if you do all of those, some mods may not work correctly. That won't make your game crash, but it may occur some bugs. For example, I had this problem with some maps from GCCM are being an invisible oblivion. I saw some people are complaining about it too. There is nothing wrong with GCCM obviously, it works now, but sometimes some small files of some mods gets corrupted due to the issues we just talked, it makes them work in an ill manner. The solution is again unsub-resub process I just talked about. It should be save game comp. but it is harder to detect (you literally have to play the game for that) and it is annoying, but good old unsub-resub process can fix it, and starting a new campaign always helps more, although you don't have to (not with every mod at least).

However, the last issue I mentioned shouldn't be happening much, Heck I am using 86 mods right now, modding, uploading, updating a lot of mods, testing more than 150 mods, and I only got it a few times, so don't worry but be wary, and calm down, you know the solution now. I hope this will fix your problem, if your mods are compatible, it will definitely solve it (at least if you have nothing wrong with your base game, and the solution to that is checking the integrity of the game files, or cleaning the game with a program like revouninstaller and re-insatall it). And if your mods aren't compatible or you have doubts about it, I will update my mod lists soon enough, the non-unlocker version should be working, but I will add some alternating, experimental, big lists that I'm currently using, because they seem working at least for now.

fixed for easier reading

:3