Hello, I’m having an issue that is preventing me from opening a specific project and all the backups I have of it. Initially the project would open and after a few seconds crash. Now i get the Failed to launch editor error when double clicking the project file. I’ve tested with several backups and a fresh zipped backup.
At no point does the Unreal crashed window appear and I can’t seem to find any crash logs in the project or elsewhere.
I tried deleting the intermediate and derived data cache folders and regenerating project files and rebuilding.
This project originally existed on a different external drive so I tested moving it back to that drive. I’d think that shouldn’t matter though if I’m just unzipping the project and running it from that location that doesn’t rely on files from other locations.
I also tried disabling various plugins by setting them to false in the .uproject
I can open any other projects fine.
Unreal 5.1.1, Windows 11
Where and when did your backup work the last time?
Did you use SourceControl (always a good way to manage important projects)
What happens if you just copy CONTENT, PLUGINS, SOURCE and the *.uproject file into a new folder? Without CONFIG. And then go “smaller”. Deactivate all plugins and remove the plugins folder(in the project, not the engine)
Did you make changes to engine content used in this project?
Originally it was a 5.0 project, then I updated it to 5.1 and had it working. I haven’t used it since updating to 5.1.1.
The backup was last used on this computer on January 3rd
I haven’t used source control for anything yet, but will be learning and implementing soon…
With just the content, plugins, source, and project file I still get the failed to launch editor error upon clicking the project file. Same if I change all plugins to false and remove the plugins folder.
I don’t think I changed any engine content.
I redownloaded the zipped project from an online storage service. This same project has been used by others fine as well. Just finding it very weird that it opened a couple times and then crashed without crash window coming up and now wont open at all and just says failed to launch editor while all other projects are working fine. I also tried verifying the 5.1.1 install from the Epic launcher.
The project is very basic and uses a single level and a few plugins. Specifically OWL Streaming Toolkit and TouchEngine. I’ve updated both plugins and placed them in the projects plugins folder.
Edit:
Ok, I just found that I can open the project if I browse to the project from Unreal instead of just clicking on the project in Windows explorer. The project is doing what it was before and crashing shortly after opening it. The first time I got the Unreal crash window and it mentioned an issue with the DLSS plugin so I disabled it and now the project still crashes but doesn’t show the crash window. Looking at the crash log from the first crash it appears there are workspace elements that are failing to load. Most or all of which I didn’t have in this project originally.
This same project has been used by others fine as well.
Does that mean that they still can use this project?
Are you able to share the project?
What I can see in the crashlog: Warning: OWL Virtual Webcam is not installed on this system - Virtual Webcam module won't be loaded. Failed to load 'Y:/Unreal/Projects/Backups/f***/TouchEngineTestingB-01/Plugins/OWLLivestreamingToolkit/Source/ThirdParty/FFmpeg/bin/avdevice-58.dll'
And errors with ConnecterUEPlugin
Errors in mdl_df_chiang_hair_bsdf
I opened the project on another computer, saved it, and then brought it back to this computer and it opens fine.
I have a feeling the OWL plugin could indeed be the cause. The plugin uses an installer to install some dependencies and puts it in the engine/plugins/runtime folder. I have the plugin in the projects folder for packaging purposes. Windows installed apps still shows an older version alongside the new one and wont let me uninstall saying it can’t find the the uninstall file. It’s for UE5 though. Not sure how to fully remove this entry from the list. I no longer have 5.0 installed.
