Using version 3.0.2, set up for a Creatbot DX plus (hence build plate dimensions 300 x 250 ), I have tried to import several models that I know are large, but easily inside those dimensions. I get the warning "cannot Auto arrange, largest part exceeds build dimensions.
If I enlarge the build dimensions to, say, 500 x 500, the models will import.
Then I can re-set the build dimensions back to 300 x 250 and adjust the models position so that it is entirely within the build area and prepare to print. Everything now looks good.
Why won't Simplify3D accept the model in the first place?