[2022] Cannot Load Save Game due to missing Horizon Signal DLC

I have it in my game and it shows in my Manage My DLCs list... is it that you used to have it and it's now gone? Or you've never had it?  

Is that on both machines? Because your report reads like your laptop has it and your home PC doesn't, for some reason.  

We're still not sure what the situation is on your laptop, is that right?

My guess is it will not show in the DLC lists but be in effect in the game there.  

I really don't know. If this is not an Ironman save, it may be the save file can be edited to remove the need or mention of that DLC; you might try the good folks over in User Mods, who are more used to having to do that kind of stuff!