in a URP project after switching render path between forward and forward and creating a new material/shader editor complains that default renderer is missing but however based on the asset it seems that it exists: !image-2022-08-18-12-57-33-100.png|width=288,height=185! !image-2022-08-18-12-55-31-592.png|width=512,height=77!
steps to reproduce :
# Make a new URP project
# In the active renderer (should be HighFidelity or similar) flip the rendering path back and forth a couple of times (doesn't matter which one you end up at)
# Create a new Shader Graph > URP > Lit Shader Graph
# Right click that shader graph and create a new material with the context menu
# The error is logged, and will now happen already when creating new shader graphs

Creating materials from non-graph shaders also seems to trigger the error, but the shader asset creation itself doesn't trigger it after step 4 unlike Shader Graphs. Likely due to the fact that a Shader Graph contains a default material sub-asset.

editor version : 
2022.2.0b1, 2023.1.0a18
URP version:
14.0.3, 15.0.1

Alternative repro steps:
# Open/Create a URP project
# Create an empty Renderer Feature (Create>Rendering>URP Renderer Feature)
# Add it to the active renderer
# Create a Material

This consistently reproduces the error until the Editor is relaunched with the same project.