Steps to repro:

1. Download the attached project and open `s1Blue` scene;
2. Let the scene's lighting auto-bake;
3. When the baking is done, untoggle the "Auto-Generate" checkbox in the Lighting window;
4. Drag the 's1Red' scene from the Project folder to the Hierarchy to additively load it.

Expected result:
The scene is loaded, and the error:
`Light probe tetrahedra is malformed. Roots should be positive, but they are negative or very close to 0 due to floating point precision.` is shown once.

Actual result:
Error:
`Light probe tetrahedra is malformed. Roots should be positive, but they are negative or very close to 0 due to floating point precision.` is spawned in the neverending error loop' is spawned in a neverending loop after any of the scene events (moving viewport of Editor focusing). See attached video.
Regression introduced in the Light Probe Merging for additive scenes branch.

Workaround is to rebake the GI for the additively loaded scene or enter Play mode.

Notes:
- Reproducible only in the lighting/lightprobes/merge-additive-probes branch, which will be merged to trunk soon;
- Reproducible in 2019.3.0a5;
- Not reproducible in 2019.3.0a5 rev. b1934478c844/ branch: trunk.