Steps to repro:
1. Open the attached project and 'SampleScene' scene;
2. Make sure that you have an active Game view instance in the Editor;
3. Drag and drop the ShadowCameraMatrix.cs script from the Hierarchy to the Directional light gameobject.

Actual result:
Editor crashes. Last calls from the stacktrace:
#1 0x00000105c67d97 in CullShadowCastersDetailDirectionalThreaded(ShadowCullingJobData&, BlockRange&, int)
#2 0x00000105c67874 in CullDirectionalShadowCastersJob(ShadowCullingJobData, unsigned int)
#3 0x00000106279486 in JobQueue::Exec(JobInfo, long long, int, bool)
#4 0x0000010627b247 in JobQueue::WaitForJobGroupID(JobGroupID, JobQueue::JobQueueWorkStealMode)
#5 0x0000010626b618 in CompleteFenceInternal(JobFence&, WorkStealMode)
#6 0x000001062212f2 in GetShadowCasterBounds(ScriptableCullResults&, int, AABB&)
#7 0x00000106def357 in CullingResults_CUSTOM_GetShadowCasterBounds(void*, int, AABB&)

See attached video.

Expected result:
Editor doesn't crash. Error about the invalid input matrix is shown.

Notes:
- Reproducible in 2020.2.0a5, 2020.1.0b5, 2019.3.9f1, 2019.2.21f1, 2018.4.20f1;
- Reproducible in HDRP and URP;
- Reproducible on Windows and macOS;
- If the issue doesn't happen right away after following the steps, enable the active Game view and enter Play mode.