As a Unity Developer, you might gather assets from the art team that have designed with URP rather than HDRP. So if you face some issue like the below, do not worry about it as it is really easy to fix it.
Assets designed with URP are not compatible with HDRP, and this is the reason why this has occured.
First of all, here’s the Unity definition for URP:
The Universal Render Pipeline (URP) is a prebuilt Scriptable Render Pipeline, made by Unity. URP provides artist-friendly workflows that let you quickly and easily create optimized graphics across a range of platforms, from mobile to high-end consoles and PCs.
To switch to the URP: simply click on Package manager, Select Unity Registry and search for Universal RP and then install it.
Create a Settings Folder in the Project Window. Then right click and select — Rendering — Universal Render Pipeline — Pipeline Asset.
Click on Edit — Project Settings — Graphics and select the UniversalRenderPipelineAsset that you have just created.
And that’s it! Your materials should be updated.
If the problem still persist or you have an asset (that you added later on) which is pink; you can simply tell Unity to Render it in URP again by clicking Edit — Render Pipeline — UniversalPipeline.