Hi JD.
Yes - it is true, that by following your steps the error is produced, and that re-exporting the scene fixes the problem. So far so good
Unfortunately this error, which I described in the screenshot, is regarding an emitter and is not the error I initially wanted to report...
The initial error-report said something like 'object <component#21> has triangles with
no material - render cannot continue'.
Re-exporting the scene (or even closing and re-opening the FIRE-window) did not solve this.
The scene could not be rendered with FIRE but worked fine if send to Maxwell.
As I recall, shutting down SketchUp, re-starting the application and loading the model would 'cure' the matter, but I'm not sure...
I've saved a screenshot of this in my office, but since I'm away on holidays I won't be able to send it the next couple of weeks.
Another issue, that I also have nailed in a screenshot in my office:
Sometimes, when opening Maxwell Scene Manager, activating the Materials-tab and choosing a non-Automatic material in use, eg. an Emitter, only the Type and Roughness-settings would be shown. In Type, it would say Emitter...
If I then wanted to change the Watts or Efficacy on this emitter, I would have to choose another material-type and then re-choose the Emitter-type again, resulting in my Emitter being reset.
It is important to note, that this could happen with any non-Automatic material, not just emitters.
Unfortunately I can't send you a screenshot yet - but I will as soon as possible.
I hope you get some days off to enjoy the hot summerdays!
/Stefan