How to reproduce:
1. Ensure the Library folder isn’t in the attached “IN-146596_clean” project
2. Open the attached “IN-146596_clean” project
3. In the Project tab, right click and navigate to Create -> Material
4. At the top of the Inspector, click on shader dropdown and select the “Particles/Standard Surface” shader
5. In the Inspector, click Edit near the chosen Shader to view the Shader properties
6. Click “Compile and show code” and the compilation error may appear (it is inconsistent)
7. Observe the results
Actual result: When building (or compiling) a Material that uses the built-in Particles/Standard Surface shader, the build intermittently fails with "Internal error communicating with the shader compiler process. Error code 0x80000004 (Not connected)"
Expected result: The built-in Particles/Standard Surface shader should compile and build without the compiler process crashing
Reproducible with: 6000.3.20f1
Reproducible on: Windows 11 Enterprise (25H2)
Not reproducible on: No other environments tested
Notes:
- This bug is inconsistent (I’ve tried over 50 times and it happened only in 4 cases)
- When compilation of shaders fails, the build also fails
- Delete the Library folder before each attempt to reproduce it - otherwise Unity serves the shader from “Library/ShaderCache” instead of recompiling it, and the crash only happens during a fresh compile.