I have updated my app from 4.25 to 4.26.4 and got a WebGL error
184WebGL: INVALID_OPERATION: useProgram: program not valid
72WebGL: INVALID_OPERATION: getUniformLocation: program not linked
@arcgis_core_views_SceneView.js?v=d508d2c9:25775 WebGL: too many errors, no more errors will be reported to the console for this context.
I was able to narrow down the issues to this code
The error is gone when those 2 lines are commented out.
Is this a bug in 4.26?