If the model is imported to the scene without generating Lightmap UVs, Unity shows an error (error.jpg) and crashes. It happens when the imported model is checked "Static".

Reproduction steps:
1. Open the attached file "case_853397";
2. Open the scene "test";
3. Click on the object "NYC-new-york" and check "Static" in the Inspector window;
4. In the prompt window press "Yes, change children";
5. Wait a little bit;

Actual result: Unity crashes.
Expected result: Unity should show an error and doesn't crash.

Workaround: Before importing the model you have to check "Generate Lightmap UVs" and apply (workaround.jpg).

Reproduced with 5.2.5f1, 5.3.6p3, 5.4.2f2, 5.5.0b11, 5.6.0a3.

Verified with 2017.2.0a1 version.