STEP files won't open.

[[Cl...]]

I am trying to open a .step file in a new program. I save it as a .step file
in Solid works, and when I open it in Calypso, I change the file ext to .stp.

I do this almost every day. For some reason, Calypso gives me this error
message (Option Not Available: STEP) when I try to open the model.

[[Am...]]

I would make sure your Add-on for STEP (STEP converter) files is still active, that would be the first thing that comes to mind.

[[Mi...]]

I had this issue. Now, when I save a file in Solidworks as a step file I will change the ext. from .STEP to .stp

Works fine after. If you already have the file saved with the ext. .STEP, you can just change it to .stp and it will also work fine. I guess calypso likes the .stp extension better.

[[No...]]

Even if the STEP option is available and active, you still need to set the correct extension filter in the file selection window. By setting the filter you tell Calypso to look for one specific CAD format and nothing else. This is not the same as setting it to "all files"!
I don't know if there are other CAD types with a .stp extension, but I certainly know that such similarities exist for NX files(extension .prt). If I try to load an NX part without setting the NX filter first, it refuses to load.