Unreal Engine Issues and Bug Tracker (UE-73090) says to post here with details so here you go. I am able to repro this crash and a workaround 100% using a vanilla BP Third Person template project and importing a tiled landscape with no materials. The steps are as follows:
In UE 4.22:
- Create a new Blueprint, Third Person template project and open it
- Create a new map, save it into a subfolder
- Enable World Composition
- Import tiled landscape (8x8 .r16 tiles, 255px^2, do not flip Y, -4, -4 offset, Components: 17x17 Sections: 1x1 Quads: 15x15, 2400 x 2400 x 12800 scale)
- Load all tiles
- Set the Landscape Actor
LOD Distribution
values to 10 (LOD 0 and Other LODs) - Save all tiles
- Unload all tiles
- PIE
- Stop
- PIE (Crash)
- All subsequent PIE attempts on the tiled map will crash
Crash can be avoided by loading all tiles before PIE (not practical for a fully built map).
If steps 6. through 9. are skipped the crash will not appear until closing and re-opening the editor (and retrying PIE in the tiled map without first loading tiles).
All of the above also occurs in 4.23.
Cooked game runs fine/has no issue in 4.22.Cooked game in 4.23 has no landscape materials, but runs fine otherwise.
I can provide a sample project and/or .r16’s if necessary.