MissingReferenceException errors are thrown when exposing or hiding a ShaderGraph asset as a shader

Steps to reproduce:

1. Open the attached project
2. Select the New Shader Graph asset in the project window
3. In the Inspector window, enable the Expose as Shader toggle
4. Press the Apply button
5. Observe the Console window

Actual results: MissingReferenceException error is thrown after recompilation

Expected results: No errors or warnings are thrown when exposing a template ShaderGraph asset as a shader

Reproducible with versions: 6000.6.0a5, 6000.6.5f1, 6000.7.0b4, 7000.0.0a7

Not reproducible with versions: 6000.3.26f1, 6000.6.0a4

Reproducible on (OS): Ubuntu 24

Not reproducible on (OS): macOS 26.6.2

Notes:

• In 6000.6.0a4 the apply/revert changes buttons are not present. Changes are applied by focusing another window
• Tested with OpenGL and Vulkan