Steps to reproduce:
1. Download 1107118_repro.zip and open "test" scene
2. On the first time opening the project terrain's texture are correct
3. Close project
4. Reopen project

Expected results: Terrain's texture is correctly loaded
Actual results: After reopening the project terrain's texture is black

Reproduced with: 2019.1.0a12
Not reproducible with: 2018.3.0f1, 2019.1.0a8
Regression introduced in: 2019.1.0a9

Note: To reproduce this issue terrain must have enabled Draw Instance and in Lighting settings, auto generate lighting must be disabled.
Workaround: Make any change to terrain and then undo it.