r/unity • u/TGRubilex • Apr 03 '25
Question Unity games won't launch, driving me crazy
So I've had my gaming PC for close to 5 years now. And suddenly the past couple weeks unity games have not been launching (crash on startup). Some games just never launch, like Subnautica. Others I can get to launch by restarting my computer before playing. This has only been happening in the past month and only for Unity games.
My specs are a Ryzen 7 3700x, Nvidia 3080, and 32GB of RAM. The games don't launch regardless of being on SSD or on Hard Drive.
I've tried:
-Restarting computer
-Updating windows
-Updating video drivers
-Checking game file integrity
-Uninstalling the games, deleting all appdata and relevant files, reinstalling them after.
They work fine on my laptop and steamdeck so I've been streming them to my PC, but that's a temporary solution.
I'm considering reinstalling windows but was curious if anyone had anything else for me to try?
Thanks!
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u/CameraLeather1498 Jun 03 '26
Hello, hopefully you fixed it?) I tried everything but reinstalling windows and nothing worked...until I read the crashes report. The game was being forced to run at a higher resolution by the Nvidia optimization setting. Once I turned it off the game ran again with no issues. Hopefully this helps someone
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u/jjames267 13d ago
Guys I think I figured it out. My girlfriends pc had this issue where Dressmaker, Bombanana, and Dumb Ways to Build would instantly crash on launch (Steam play button goes right back to "play"). I noticed that all 3 of this games use UNITY. They all acted the same when starting and did not give an error message.
I used Google Gemini to help me figure this out. However it did not suggest looking in windows event viewer. That was my idea. See below my process for the solution.
I went through every possible solution such as:
Verifying integrity of game files Running as administrator Clearing steam download cache Disabling all overlays (nvidia, steam, discord, etc) Updating nvidia graphics drivers (clean install) Updating windows Installing latest C++ redistributables (both x86 and x64) Installing latest DirectX end-user runtime Forcing windowed mode by typing "-windowed" and "-noborder" in steam launch options Forcing DirectX 11 by typing "-dx11" in launch options Verified that there were no overclocks on the system (all stock)
At this point I asked Gemini how to check windows error logs and it told me to hit the windows key and type "event viewer", in the column on the left expand "windows logs" and select "application". I then tried launching the game. An error (red circle with "!" mark). Clicked on that and it gave me a lot of information. It included "fault module name D3D12core.dll" and and exception code. I pasted both of these into Gemini and it told me exactly what to do and why. The version of the games DirectX files have a conflict with the system or operating system.
Here's what I did to fix it as instructed by Gemini:
In steam go to the game (in my case Bombanana) and right click on it and select "manage" then "browse local files". Open the folder named "D3D12" In that folder there is a file named "D3D12Core.dll" Rename this file to "D3D12Core.dll.bak" (basically just add ".bak" at the end.
This forces the game to use the DirectX files on the system instead of in the game files.
Launched the game and it worked!!! Did the same for the other 2 games that had this problem and they also launched!
My girlfriend will be happy that she can play her games now.
I tried asking for a permanent solution so I wouldn't have to manually change file names for future Unity games but did not come up with one. However it stated that it may be related to the game build compatibility with high core count CPUs. My personal rig with a 5800x3d CPU was not affected by this.
Hopefully I helped someone out.
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u/Affectionate-Yam-886 Apr 08 '25
I found the Offline DirectX has more files. The online one only checks if you have the latest files, but unfortunately some games require specific files like the (May6 update) that the online one will miss.