Hey @DazzaJay — thanks for sharing the video, and yeah… that’s a gnarly bug. We’ve run into similar issues during UE 5.5.x testing too — especially around materials going black or showing fallback shading until manually reloaded.
What’s Likely Happening:
This seems to be a streaming/rendering sync issue, where the shader or texture reference is momentarily invalid or skipped during viewport traversal (often triggered by memory spikes or engine state lockups).
Some Things You Can Try:
1. Recompile Shaders + Clear Derived Data Cache
– Sometimes stale compiled shaders cause assets to fail to resolve visually.
– Try: r.ShaderPipelineCache.Clear and manually clear the DerivedDataCache folder.
2. Increase Texture Streaming Pool Size
– Black textures can indicate streaming pool exhaustion.
– Console command: r.Streaming.PoolSize 2000 (adjust to your GPU VRAM)
3. Check for Engine Locks or GPU Driver Spikes
– If the engine freezes momentarily, and then assets lose state, it could be memory paging or driver latency. Monitor with stat GPU and stat RHI.
4. Disable Virtual Textures (temporarily)
– If you’re using virtual texturing, try disabling it as a test (r.VirtualTexture settings).
Bonus Tip: Keep Track of These Bugs Across Assets
In teams or larger scenes, this issue can hit some meshes and not others — which makes it easy to lose track of which materials are affected.
That’s part of why we built Asset Optics — a plugin that helps you:
Attach bug notes or comments directly to assets like “black material bug seen on this mesh”- Create checklists per asset for testing fixes across engine versions
Sync those notes with your web dashboard, so you don’t forget what was already debugged
Helps a ton when you’re testing across 5.5.0 → 5.5.1 and need to track visual regressions without relying on memory or screenshot folders.
Let us know if any of the fixes help — or if you want to share a project excerpt, we’d be happy to help isolate the root cause further! 