To reproduce:
1. Open the attached project
2. Open "DemoScene" in Assets\Voxeland\Demo\Scenes
3. Select Voxeland Game Object
4. In the Inspector, in the Voxeland script component, expand the "Mode and Ranges"
5. Set "Editor mode" property to "Static"
6. Set "Playmode Mode" property to "Dynamic Limited"
7. Set "Terrain Size" to 2000 (it will be automatically downsized a bit)
8. In the same Voxeland script component click the "Rebuild" button

Desired outcome: Progress completes successfully.
Actual result: Message box "Fatal error in GC: Too many root sets" appears before the end of the progress. Editor crashes few seconds after pressing "OK" on that message box.

Stack trace:
GC_add_roots_inner
GC_add_roots
mono_gc_register_root
thread_startup
mono_profiler_thread_start
start_wrapper_internal
start_wrapper
inner_start_thread

Reproduced with 2017.1.0b6, 2017.1.0b9, 2017.1.0b10, 2017.2.0b4
Not reproduced with 5.5.4f1, 5.6.1p4