Most of the time getting error

[vangel]

For 95% of the scenes I'm getting this error during removing calculations, then the calculation (remove shadow and/or remove shading) stops with no result

Error: Levels empty :
r = 0

I can't seem to determine the difference between the scenes where it run and the majority where it doesn't.
Using scanned models (obj) from multiple sources.
Tried small models (<100000 faces) with small textures (=<4096 ^2) but the face count or the texture size have no influence on the outcome.

What can I do to get it working?

[Alexey Pasumansky]

Hello vangel,

Which build number of the application you are using?

Can you share the DLZ project with the imported model and drawn illumination maps with support@agisoft.com, so that we could reproduce the issue and check what is wrong?