I kinda understand what it says, but not why it happends or how to fix it. It says that a parameter/texture is missing from the enigne itself, but i have no idea how to fix it.
I have tried to rebuild all the shaders by removing the DerivedDataCache folder, using the Shader Compile Worker and both r.ShaderDevelopmentMode=1 and r.RecompileShaders CHANGED commands, but nothing.
Its a new virtual production project with barely some blueprint code and assets, but due to difficulties in calibrating everything (cameras, ArUco markers…) i really, really want to avoid to create a new project.
Try deleting the Intermediateand DerivedDataCache folders. The project should rebuild the shaders. If any of them were corrupted then they should be fixed.
You can also try verifying your unreal install from the epic launcher, in case any of the built in shaders have gone bad.
I’ve tried both options, but it didnt work. Verifying the files doesn’t seem to do anything, or doesn’t find anything broken and the shaders were rebuild, but it still crash.
Is there any way to open the path and copy-paste the file with another one from a similar/backup project or something like that?
What are your pc specs. Does your graphics card meet Unreal’s requirements?
If you are using an nvidia GPU have you tried the studio drivers, or rolling back to a previous version of the drivers?
If on a laptop make sure unreal is using the dedicated GPU and not the integrated version on the CPU
Are you using lumen or baked lighting? It seems like a shader is broken somewhere. Are all of your materials compiled correctly? Do you have any instances of materials where you have errors and a yellow exclamation mark at near compile?
I’ve 32 RAM, AMD Ryzen 9 3900 X and RTX 4070 Ti., Nvidia Driver 552.22 (i’ve tried the newest one anyway).
After a few tests thanks to your comment, it looks like Lumen is the source of the crash. If i change “Dynamic Global Illumination Method” to None , Screen Space or Ray Traced, the project doesnt crash, but the viewport becomes black in Play Mode; if Lumen is enabled again, it crash again. Reflection Method using Lumen doesnt crash the project either.
Also, i have checked each Material and Material Instances and some were broken (missing a bink file, a mistake in my end while migrating files) but now they are all working, but still crashing.
It seems like a bug at this point if most user influenced decisions can’t really change the situation. Perhaps the combination of hardware is causing a glitch of some sort.
Could some other program be interfering with unreal in any way? A real-time virus scan / windows defender blocking access mid calculations to files?
Is your power plan set to adaptive or high performance? Maybe setting the gpu to not go into power saving might help. (sometimes the ramp up time can cause errors in programs)
No AFAIK, i have turn off the virus scan and my PC is used just for virtual production, there is no “random” software that could interfere with Unreal Engine.
I changed the power plan to High Performance just in case and i will upgrade the project to UE 5.4 just as a last resort
Updating the project to 5.4 did work (kinda). The project no longer crash even with lumen , but the viewport becomes black in Play Mode (fixed by changing the Play Mode to Simulate)
I didnt see any problems with the exposure, but i changed the play mode from “Selected Viewport” to “Simulate” and now i can see. I dont know how Simulate will affect my project, but at least it doesnt crash, i can see and i have inputs, so fair enough.
No, or at least i didnt add a post process volumen at any time.
The only change i’ve made between my backup and my current version was the configuration of some Lens File to work with some ArUco Markers and the Live Link plugin.
