Repro steps:
1. Download Realistic Effects Pack 4 from Asset Store
2. Open PC_Demo(Unity5.5+) scene
3. Press Play and click on the Day/Night button to switch to night
4. Press Next Effect until Effect4_Optimized is playing.
5. Observe console error and visual artefacts.

Assertion failed on expression: '!params || ((params->vertexCount * params->stride) + params->vertexOffset) <= (chunk->writtenVertices * chunk->stride)'

Notes:
- Found during Asset Store Bash for 2017.1.
- Issue originally not found in 5.6.0p1 with the large project, but the smaller repro project attached in the comments reproes in 5.6 and in 5.5.