I save a part as a step file, but when I open it, some feature miss. why?
Are the features that are missing surfaces? Solids? Sketches? Or something else?
You could run "Import Diagnostics" on the part. Save beforehand though. It is painfully slow and can sometimes cause crashes but it will show you all the issues that could not be solved correctly from the original geometry and sometimes you can fix them as well.
..as a test,.. export as a parasolid (native kernel) and open/import the parasolid... what do you see, is the feature missing?
Can you post your step file here ?
Is the original Part a SolidWorks Part ? Did you make the part with surfacing and there would be surfaces that are not knitted etc... ?
Do you mean the features are not showing on the part or are not showing in the feature tree?
What type of step file did you save it out as?
There are 2 types - look at these posts.
Step file typeswhat file type should i use
Step file types
Retrieving data ...