Not sure if anyone can help, and we know this issue has been presented before; Running an x64 box we’ve searched the interwebs and tried every solution out there we could find. Win 10 completely up to date, all .Net’s installed, all Redistributables installed, folder permissions granted, attempted manually running Prereqs w Admin, and finally attempted running MS’s “Program Install and Uninstall Troubleshooter” which did find the Prereqs attempted install but couldn’t resolve the issue. Just looking for anything we might have missed. We’re still able to launch UE4Editor.exe manually.
Since it doesn’t seem like anyone aside from us are having this issue; possibly an isolated issue.
Well I got the same error… all you have to do is restart, after you update from 4.20.2 -> 4.20.3
Annnndddd, that solved the problem… have fun
Happy Developing
Unfortunately, we have restarted many times after upgrading (and reinstalled many times over), and still get the same error upon Launching both 20.2 & 20.3.
Glad that solved it for you guys though; no luck for us in that department. Support suggested running MS "NET Framework Repair Tool’ which also did not resolve the issue.
What I did was go in task manager and make sure that there was no instances of unreal engine running then right click on the Unreal Launcher shortcut properties and add " -SkipBuildPatchPrereq" at the end of the target path. Then it worked fine.
It should look like this “C:\Program Files (x86)\Epic Games\Launcher\Portal\Binaries\Win32\EpicGamesLauncher.exe” -SkipBuildPatchPrereq
Make sure you kill all processes named UE4Editor.exe then try relaunching again if it doesn’t work. Best of luck
If you’re experiencing this problem, please try a system reboot to see if that helps. We are working to address some issues regarding the pre-reqs requiring a system reboot, and depending on different scenarios either automatically rebooting without warning, or failing to reboot and thus failing the pre-req installs. (tracking as OPP-10323)
Also you can try disabling your UAC and set the launcher to run as administrator, after this if all else fails just uninstall the engine then reinstall, worked for me before.
One other thing that worked in the past was choosing different graphic card drivers, I had to revert back my AMD card to Radeon 18.5.1 drivers because the Radeon 18.9.3 drivers gave me this same problem. Sorry I keep tossing out all these things to try but I had this problem so many times before and it’s always something different that fixes it, it seems.
This is actually the only thing that worked for us. **Cipher5 **you are a god. I guess it’s akin to running the editor manually, but being able to launch with the actual Launcher is pretty great again. We think you may be right about it being somehow related to a driver issue, since there has been some issues with Nvidia and UE4 lately. We had to rollback two updates (NV 3.99.24) to get Unreal to stop flickering to black screen when rolling over icons (on all our computers)…
What I did was go in task manager and make sure that there was no instances of unreal engine running then right click on the Unreal Launcher shortcut properties and add " -SkipBuildPatchPrereq" at the end of the target path. Then it worked fine.
It should look like this “C:\Program Files (x86)\Epic Games\Launcher\Portal\Binaries\Win32\EpicGamesLauncher.exe” -SkipBuildPatchPrereq
Make sure you kill all processes named UE4Editor.exe then try relaunching again.
This worked for me…took a while to load but it’s working NOW!
Came here to find the solution and while reading throught the posts and googling things as I went MS UAC interrupted asking me if I wanted to allow UE4 … prerequisites … to alter the computer. This was at least 5 or more minutes after trying to launch. Clicked yes and the game engine loaded (took a while).
