Can't import STEP files via Import Mesh

[GRSnyder]

If I remember correctly, this used to work just fine. But now, the imported file previews correctly, but the OK button to actually complete the import seems to always be disabled:

Also, the "Numerical Inputs" disclosure triangle seems to contain nothing inside it.

It is still possible to Upload STEP files into the data browser successfully.

Attached is a little STEP file you can reproduce with, but the problem seems to occur with pretty much any STEP file. 

[TheCADWhisperer]

STEP format is not an obj or stl mesh format.

[GRSnyder]

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@TheCADWhisperer wrote: STEP format is not an obj or stl mesh format.

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Indeed. But it's evidently an almost-supported format for this operation, as evidenced by the fact that the files preview perfectly. Shouldn't it either work or not? 

Upon further investigation, F360 does let you pick any file for Insert Mesh. But if it doesn't understand the format, it does nothing silently, which also seems wrong. No error message, nothing. STEP does seem to receive special handling.