Paradox updated its HoI4 launcher after the 1.8 version, but many folks who were playing the game previously have had issues trying to use mods like Kaiserreich with it. They get messages like being told the mod is still only valid for 1.8, or being told they don't have a proper descriptor file.
This can be frustrating, but the good news is there are some ways to deal with the problem!
First Thing to Try
- Unsubscribe from all HoI4 mods (yes, all of them)
- Find the folder where your HoI4 saves are kept (it's probably going to be in your Documents folder, some variation on C:\Users\YourName\Documents\ParadoxInteractive\Hearts of Iron IV -- once you get there, you'll see folders for "logs", "save games", "mod", etc.)
- Delete the mod folder and everything in it
- Delete a file called mods_registry.json
- Now re-subscribe to your mods and proceed
Doing a Clean Re-Install of HoI4
If the above doesn't work, we'd advise doing a complete, clean re-install of Hearts of Iron IV.
We have a full guide on how to do that here.
Paradox's Troubleshooting Advice
Paradox is aware of the issues users are having with the new launcher, and have their own troubleshooting advice, so looking into that is another option.
You can find it here.
Other Install Methods
It can be worth trying other methods of installing the mod if one isn't working. You can find all the download links to Kaiserreich here.
Issues with Using Other Drives
One known issue with the new launcher is that it doesn't play nicely when you use non-standard partitions for your mod folder and HOI4, or using any folder redirects. If you are doing that, installing HOI4 on your main partition (for most PC users, this is your C: drive), keeping your mod folder there, and not using any folder redirects, can help.
If none of this helps the best thing you can do is talk to Paradox tech support - ultimately the launcher is something they created and know far better than we do, so they are best placed to help.