Steps to reproduce:

Create a new project from the Universal 3D (URP blank) template
Select Assets > Create > Shader Graph > URP > Lit Shader Graph, press Enter, and double-click the new Shader Graph to open it
Select Assets > Create > Scripting > MonoBehaviour Script, press Enter, and wait for the script compilation to finish
Observe the Console

Actual results: An exception is thrown after the script reload

Exception: PreviewManager was not disposed of properly.
   at UnityEditor.ShaderGraph.Drawing.PreviewManager.Finalize() in ./Library/PackageCache/com.unity.shadergraph@4cc5d8877824/Editor/Drawing/PreviewManager.cs:line 1539
   at System.GC.RunFinalizers() in /Users/bokken/build/output/unity/dotnet-runtime/src/coreclr/System.Private.CoreLib/src/System/GC.CoreCLR.cs:line 326

Expected results: No errors are thrown

Reproducible with versions: 7000.0.0a9, 7000.0.0a10

Not reproducible with versions: 6000.0.84f1, 6000.3.27f1, 6000.6.7f1, 6000.7.0b6, 7000.0.0a8

Tested on (OS): macOS 26.6.2

Notes:

Also thrown with a Shader Sub Graph open
The error is logged when the old window data is garbage collected, so it can appear only after the second recompilation; if nothing is logged after step 3, repeat step 3