Engine crashing frequently while working in material editor graph and material have no dependencies yet. It’s really frustrating
Version : 5.7.4
OS : Windows 11
Cleared the project cache folders and still the same. Can some one tell me what’s going on with engine
Hello there @Origins!
This is a peculiar scenario, just dragging to create a new node crashes the whole thing. The crash screen does give us a few clues, though:
Assertion failed: (Index >= 0) & (Index < ArrayNum)
Array index out of bounds: 0 into an array of size 0
This error means that the engine is trying to access a data array, and finds it empty. And since the related trace aims at “UnrealEditor_Engine”, that’s coming from the engine itself, not from project’s code.
The most likely cause is corruption, even if you already cleared the project’s cache. Yet, there’s one element that can still hold invalid data, and that’s the engine’s own cache. To clear that one out, you need to go to your system’s local data, usually at %LOCALAPPDATA%\UnrealEngine\Common. There, delete the DerivedDataCache folder, then start the engine again, open an empty project, and test a new node.
Alternatively, if the issue persists even with the engine’s cache cleared, then I would verify the whole installation. To do that, from the launcher, locate your install, open the drop down menu, and click on “Verify”. The process should repair any broken element that could be causing this.
I had exactly problem in UE5.7. Problem’s solved by re-installing the engine. Probably due to too many minor issues stacking all together, verifying and deleting certain files wouldn’t work.
Sorry you’re dealing with this — frequent Material Editor crashes in UE 5.7.4 have been reported by quite a few people lately.Even with no material dependencies, the Material Editor is one of the most unstable parts of 5.7 right now.Quick Things That Have Helped Many:
Disable Shader Caching / Precompilation Features
Go to Project Settings → Rendering → Shader Compilation.
Set Shader Compiler Worker Count to a lower number (try 2 or 4 instead of default).
Disable Shared Material Shader Code and Precompile Material Shaders if enabled.
Material Editor Specific Fixes
In the Material Editor, go to View → Show Engine Content (sometimes helps).
Try working in a new blank material first.
Avoid using Material Functions or complex node graphs while the issue persists.
Switch the Preview Scene to a very simple one (e.g. Basic or Empty).
Other Common Fixes
Update your GPU drivers (especially if using NVIDIA — do a clean install).
In Project Settings → Rendering, try switching Default RHI between DirectX 12 and DirectX 11.
Disable Nanite and Lumen globally while working on materials.
Turn off Virtual Shadow Maps.
More Aggressive Cleanup
Delete these folders (in addition to what you already cleared):
Saved/ShaderCache
Saved/ShaderWorkingDir
Intermediate
Then regenerate project files and restart.
Check Logs for Clues
When it crashes, go to ProjectFolder/Saved/Logs and open the latest .log file.
Search for “Material” or “Assertion failed” near the end and post the last 10–15 lines here if possible.
UE 5.7.4 seems to have introduced some regression in the Material Editor for several users. Many people are waiting for 5.7.5 or have temporarily moved back to 5.6.Let us know:
Are you using NVIDIA / AMD / Intel GPU?
Do you have many custom nodes / complex expressions in the material?
Any specific node that seems to trigger the crash?
Hang in there — this is currently one of the more painful bugs in 5.7.
In my case none of the above fixed. It’s PCG-Ex plugin conflicting. I removed from plugin folder and suddenly everything is normal.
Thanks for the response BTW
