[kami]

I've got a problem lately with some files, where the updating of the material preview sometimes takes ages (several minutes before it starts). Even on simple materials without textures.
The whole rhino is non responsive during this period.
Did anybody experience the same problem? It feels pretty new to me ...
I haven't tested if it happens only specific files and if it always occurs in this files, but I'll observe it in the future.

[JDHill]

The only condition I know of that matches that description would be if you had some file paths pointing to invalid network locations. If you are indeed able to find a specific 3DM where it happens consistently, I'd like to see that file.

[polynurb]

if you have fire running (on many threads) and/or are rendering in the background AND have the preview engine set to 1 thread or so, it may eventually take very long before the preview starts to get free CPU cycles.

i have see it delay for 30sek or longer before due to that. it helps to turn on full threads on the preview engine.