Open creo file with older version software

See this PTC article on GCRI.

Article - CS34964 - About GCRI: How to open files created in newer release, in older version of Creo Parametric (ptc.com)

Please look at this link.

http://www.clausbrod.de/cgi-bin/view.pl/CoCreateModeling/OsdmFaqFileHandling#fileversion 

https://www.cocreateusers.org/forum/showthread.php?t=6399&highlight=bin-io-revision 

(BIN-IO-REVISION :MR-13-RELEASE) 

MR-13-RELEASE will be replaced by your version.  You will need to look help About to find your older version.

You can save as an older version greater than one version older.  There is no guarantee of perfect save, but it works far better than having to export a step file.

Tom