Reproduction Steps:
1. Import attached project.
2. Open Test scene.
3. Build and Run.
4. In Standalone Build Data files, open output.log.

Expected result: Allocator errors should not be shown.
Actual result: The following error appears:
"Internal: JobTempAlloc has allocations that are more than 4 frames old - this is not allowed and likely a leak"

Note #1: If trees are removed from terrain, the error no longer appears.
Note #2: No obvious memory leak is detected.

Reproducible with: 5.5.3f1, 5.6.0f3, 2017.1.0p2