Are Cubase .CPR versions backwards compatible?

Say for example… if one person is using Cubase 6, 7 or 8 and working on a song, and wants to send that project to another person using say, Cubase SX3, can they open the song file from a higher version to work on? I have to assume yes, that any version using .CPR is compatible both ways.

Not exactly. I have had issues trying to open a newer cpr file in an older version.

When it WAS the days of SX3 and Nuendo 3, I was able to transfer projects from home to studios without issues. Older or newer. Recently it’s been hit and miss though.

Official statement:

Thanks Mike for sharing your experience that it didn’t work for you.

And thanks Jarno for that link. According to that graph, it looks like the answer, along with Mikes reply is a big NO.

SX3 can’t open anything above that…not projects from C4, C5, C6, C7, nor C8.
Nor can C4 open projects from C5, C6, C7, nor C8.
Nor can C5 open projects from C6, C7, nor C8.

It looks like C6 can open projects from C7 & C8, and C7 can open C8 projects. I would have that .CPR files would be interchangeable between all versions that use the .CPR file both ways…glad I asked. At least higher versions can open files from all lesser versions that use the .CPR, but a bummer for people with higher versions that want to work with people using lesser versions.