CONVERT .PVS file for .IGS or STEP

No sure, I have tried myself. but still looking into it. 

good luck. 

How are you opening the file? It sounds like maybe you're double clicking the assembly file in a folder, and it launches Creo View?

Have you tried using the Open command in Creo, browsing to the file, and opening it that way?

Regardless, is that wise? Conversion of a conversion. You're bound to introduce errors and inaccuracies. STEP or IGES should created from original source if possible.

Go back to the original problem instead of creating more problems on top of problems.

Why is the assembly not opening? Using File - Open and navigating to the folder? Does it give you any errors?

Was the file created via "save as creo file" from another program, like solidworks or inventor? PTC has "blocked" that sort of import, according to them to prevent data errors. If the file needs to be exported from a different software, export it as step or iges so it can be imported in to creo parametric.

Using file manager, navigate to the file, RMB and use Open with and select notepad (or other text editor). It should have something like this in the header listing what version of Creo Paramtric it was created with. 

Was the file a "save as creo file" from another program, like solidworks or inventor? PTC has "blocked" that sort of import, according to them to prevent data errors. If the file needs to be exported from a different software, export it as step or iges so it can be imported in to creo parametric.