Do you know, that… ?
By opening imported files (e.g. *.step, *.iges, *.x_t) window appears import diagnostics. Of course, the file should be checked for errors and possibly fixed.
Next (by default) a second question box also appears: Do you want to continue with the operation recognition?
Probably most of you choose the option No. And so every time… so this window can be turned off permanently.
How?
ticking Don't ask again. You can also turn it off in the options by unchecking it Prompt for feature recognition when opening a part.
This message is generated by the add-in FeatureWorks used to recognize operations in imported files. Someday I will try to show it closer and tell, when is it worth using. Certainly, in the case of complex shapes, you can skip using it. Because, that recognition algorithms cannot handle such shapes, but for simple solids they do quite well.
All right, let's assume, that the message has been disabled. But what about the situation, when we want again, to appear? Then turn on Options appendix FeatureWorks by clicking on the import in the tree.
And check the unchecked option again.