Invalid Worksession

I received a few .RWS files from an associated architect and I am not able to open them. I get the error:
Invalid Worksession

It’s possible these files were created with a different Version #? I am running version
Version 5 SR11 64-bit
(5.11.50226.17195, 2/26/2015)
Is there a way I can find out which version the RWS files were created in?

The files are also very large: 200 megs?