I was working on one of Unity's tutorial projects(the cute nightmare survival one) and wanted to add something cool using Lightweight RP. But upgrading to Lightweight RP messed up my textures. Apart from turning to everything pink when I go Edit>Render Pipeline>Lightweight RP>Upgrade Project Materials....; some of the objects still remain pink and when I manually set their shader the original texture is lost. I am currently using Unity 2019.2.
Before using Lightweight RP
After using Lightweight RP
These are the options I am getting for my shaders. Selected the 'lit' option.
Also it would be really helpful to do something about the lighting as after LRP it gets really dull and also I have an in game option for setting the brightness of the game which becomes useless after upgrading.
You can no longer use the standard shader. What I did was open my 3D model in blender and redue my materials. If you cant do that I think you can use the render pipline shaders instead of the standard