Can play but not save C5.5 projects in Cubase 6

I can open a Cubase 5.5 project in Cubase 6 (64-bit), and play the project. Then on first instance, I can hit “save” and C6 will throw up a prompt asking if I want to save the project in C6 format. After this is done, the project plays successfully, I can close it and re-open it.

However, if I start any additional work on the project, and then try to save the modified file, Cubase 6 freezes. Does this over and over again. The project file is roughly 4GB in size; of this, only 39kb is saved to a new file as the program hangs.

I’ve updated the VST paths in Cubase 6, and to my knowledge, set all other preferences in line with those used for my Cubase 5.5 projects.

Cubase 5.5 still resides on the machine, in a separate folder. It is not being run concurrently with Cubase 6.

Using Windows 7 ultimate, 64-bit, MR816CSX audio interface.

Any thoughts from the group?

A truly lovely program; just having some installation issues.

Thanks

Not sure about the freezing . . .

but what I have been doing with C5 projects is opening them in C6 - then backup the project to a new location - including all audio, video, no truncation of files, etc. - and work on the new C6 “backup”.

I’m not quite confident yet that I won’t encounter some strange issue of incompatibility in the converted project and this gives me the option to go back and finish in C5, if needed.

I guess I’m just paranoid.

Hugh