This won't be fixed, this is because LWRP isn't compatible with previous shaders, and Standard Assets are deprecated after 17.x (they are removed from 18.2, 18.1 still have them in the installer because they couldn't be removed for that version yet. Asset Store version mark them as 17.x only)

Standard Assets are being deprecated, but some of the included packages are being remade as their own standalone packages on the store or through the Package Manager, e.g.
- Vehicle -> Vehicle Tool
- ParticleSystem - > Particle Pack
- Image Effect -> Postprocessing Stack
- Camera -> Cinemachine

//
Steps to reproduce:
1. Download and open the attached project
2. Add any water prefab into the scene

Result: crash

OR

1. Create a new project with Lightweight Render Pipeline template
2. Import Standard Assets

Result: all water shaders are broken, invisible in the scene

Reproduced on 2018.1.3f1, 2018.2.0b5, 2018.3.0a1 on LWRP 1.1.15