STEP reload from disk results in error

[phansel]

Identical to: bambulab/BambuStudio#9226

Right clicking and selecting "Reload from disk" on a STEP object imported with default parameters results in an error:

This error does not occur when reloading STL files from disk.

This error also does not occur in PrusaSlicer 2.9.6, so it seems it has been introduced since BambuStudio was forked from Slic3r/PrusaSlicer.

QIDIStudio Version: 2.4.0.70