IGES and STEP File Import/Export Problem

[Anonymous]

Greetings,

I have an issue on importing or exporting the IGES and STEP File in AutoCAD Mechanical 2013. When I click IMPORT, there is no options to select IGES and STEP in the files of type box. I've tried to type IGES, IGESIN, IGESOUT, IGESIMPORT, IGESEXPORT, but the systems says they are unknown command. So I could not import or export anything from IGES and STEP file.

It was not a problem importing IGES and STEP file until my AutoCAD Mechanical suddenly crash and shuts down. When I restart AutoCAD, the problem appears. 

Somebody please help. I really appreciate your kindness.

Thank you.

[Anonymous · Accepted solution]

Found the solution. Actually the CMDDIA value was changed to 0 instead of 1. I'm not sure why this happened. But when I change the value to 1, everythings seems came back to normal.