Forza Horizon 4 won't launch

Well somehow I've managed to fix it! Still not entirely sure what did it, but let me walk through the process.

I don't want to give anyone the idea that I have found THE solution for this. I feel like I might have been really lucky and did 'something' right. Let me start off by saying that I don't know how to fix it. All I can tell you are (by memory) the steps that I still remember I took that led me here.

So I did refund the add-on which didn't solve the problem.

After uninstalling and resetting the game for about 5 times, I figured there might be some stuff left on the disk after uninstalling so what I did was I searched the PC for 'forza' using Everything Search (Google that). This is basically a fast search tool for Windows. Then I deleted all the things I could with Forza in it. Maps, files, images. Some things couldn't be removed. Especially the files in a folder called WindowsApps.

What I did was I right clicked this folder and went to properties > Security > Advanced.

This screen showed up. I clicked Change:

The next window showed where I clicked Advanced:

Another new window opened. I clicked 'Find Now' and double clicked on my Windows Account:

The next screen showed up with my name in it, I clicked OK and on the next screen also OK:

This gave me the rights to delete the contents from the WindowsApps folder. I searched for anything that had to do with Forza (sunrisegame) or the DLC or Forza Cars and deleted it.

Then I went into the Registery and searched for 'forza' I tried to delete anything I came across referencing to Forza in the register. Then I restarted.

Let me be very clear here. I felt like I had nothing left to lose and if this would break my Windows installation then so be it, but usually just removing stuff from the Registery isn't a great idea if you don't know 100% sure what you're doing. ALSO I'm not sure if this fixed the game, but if you're still curious then please read on...

I restarted my PC after doing all this and tried downloading Forza again, but this time on another disk just to be sure. This did not work. I'm pretty sure I broke something, making it seem like the game was installed, but it actually wasn't. Anyway I tried many things now since I couldn't correctly install the game anymore. I tried resetting the windows store and the Xbox Beta app and it didn't seem to work. At some point I deleted everything again and tried to reinstall the game again. To my surprise the installation process only took seconds (For a 74 Gb download) and I couldn't immediately find why. After a while I realized that the game wasn't uninstalled correctly. All the data from the installation was still on the disk so I manually deleted it. Now I reinstalled the game yet again. Took several hours to download. I picked the old disk where I always installed the game as source for the game and waited for it to be installed. Suddenly the game worked...

These are the things I love/hate so much about these things. Ofcourse I am very happy that the game is working right now, but I don't know what actually fixed it and what the actual issue was. I feel like the issue is that the game makes a Registery entry somewhere or maybe adds some files that screw up the installation. Only by deleting those files/registery keys you get to play again, but then again, I'm no expert.

I really hope this is helpful for you. I still have the escalation ticket with the support and I will await updates from them too so if I hear anything new I will let you know!

hi good luck! I had all that but all they do is put you on to another agent,in my case they went through all they knew then said I need a windows reinstall, as it was 2am in morning I postponed. They all seem very helpful but cant get this problem sorted. If you have any luck please let us know.Thanks

Hi all,

I have the same problem. Also already tried everything and spoke with 3 or 4 different MS agents. Last thing they did for me was to 'escalate' the issue, whatever that exactly means. This happened after an agent did a remote desktop connection and tried some stuff I already tried before. I'm about to initiate a new chat since they said it can take up to 72 hrs before I hear something new and it's already been that long. I'll let you all know if I find a solution!

Edit: Great, turns out my case wasn't escalated at all. The kind person I spoke to just now escalated it for me and will keep me up to date. I told them to add the link to this thread right here to the person that handles the escalations since there are more people with the same problem. I'll keep you posted!

Never going to beat them.its small fry trying to chase the big fish. (Theres a thought for a new game) all we can do is try for refund and try to warn others not to get addons. If only i hadnt got the add ons.my grandson loves the game and spent ages building up over 2 million cr to get his favourite car. He is so gutted now we cant even launch the original game. And i can only try refund on add on.  If anyone does get a fix please let us small fry know.

They're an absolute joke, I went and wrote a nice ticket, explaining them the issue in detail, which steps I have done, what Microsoft support said to me, and how there are more people with the issue, even pressed them to stop following protocol for a second, and just to tell us what's up or if we're ever going to get the game back working, or if there is any fix in the make or it being investigated. They responded by putting the ticket as solved. I've lost all faith, I'm going for that refund and staying clear from any Forza games in the future. 

yea literally the same, asked them are there any news and how this should be a priority to fix and all of that, wrote 2 long messages and they just put my ticket as solved aswell, so I attacked them now and wait for them to asnwer.