3d-building-tiler lack of error message

1. A concise explanation of the problem you're experiencing.

No error msg when 3d-buildings-tiler crash

2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

4. The Cesium version you're using, your operating system and browser.