I’ve read the Steinberg post on how to do this, going via SL / SX. That post is now locked, so I cannot comment there. However, when I try to import a VST project into SL, all available VST projects are greyed out, so I get nowhere.
Where am I going wrong?
I never heard anything about SL doing this myself (?), but I do know that Cubase SX3 is able to import Cubase VST 5 projects. To get from Cubase VST 5 projects, all the way to Cubase 5, I do know Cubase SX3 has to go inbetween. I don’t know if Cubase SX1 or SX2 can be used for this (?).
I also thought I read you can download SX3 for free from the Steinberg site…as long as you can prove you own any Cubase version higher than that.
Also I believe you need to use ‘save as’ to each time you make the transition from one Cubase version to another, unless you never want to open the old project in the old Cubase version(s).
I really don’t know if say, Cubase VST 3, 4 can be imported to SX3 (or any SX versions). I got into Cubase starting with Cubase VST 5/32, so I never bothered to read up on earlier Cubase versions.
That’s all I know, some one with more experience & knowledge can correct me if I’m wrong.
OK - so I didn’t fully explain the Steinberg recommended method, which is copied here:
Re: Cubase VST Song import in Cubase 4/5: a solution
by Steinberg Service » Mon Jun 18, 2012 12:01 pm
Dear Cubase customers,
Cubase 4, 5, 6 and also 7 do not support the import of Cubase VST songs and projects anymore. In order to import your older Cubase VST projects and songs, you can install Cubase SX3 / SL3 / SE3, which are available as a download here:
Cubase SX 3
Cubase SL 3
Cubase SE 3
Cubase SX3 / SL3 / SE3 can be run with your current Cubase licenses and allows you to import VST projects, save them in the new *.cpr format and open them in current Cubase series. These are not officially supported under current Windows OS but should install and run just fine under Windows Vista / 7 / 8.
Please note that Cubase SX3 / SL3 / SE3 are PPC based versions and the latest Mac OS to run PPC applications is OS X 10.6. For Mac installations please be sure to install the eLicenser Control Center for Mac OS X 10.5 (PowerPC and Intel based), 10.6 and 10.7, which can be downloaded here.
My projects were created with VST 5. My issue is that when I try to import them into SL3, which I have downloaded, all projects are greyed out. I am working with OS 10.5, so according to Steinberg it should be compatible.
I’m wondering if your Cubase ver. 5 license is not being recognized by SL3 being your VST 5 projects are greyed out…maybe you haven’t made that step of licensing merging, or it’s identification correctly 
Please note that Cubase SX3 / SL3 / SE3 are PPC based versions and the latest Mac OS to run PPC applications is OS X 10.6. For Mac installations > please be sure to install the eLicenser Control Center > for Mac OS X 10.5 (PowerPC and Intel based), 10.6 and 10.7, which can be downloaded …
I’d be thinking about deleting SL3, and trying SX3 just for the hell of it. I say this only because we had no problem at all importing VST 5/32 projects into SX3. I’m also assuming that regular VST 5 & VST 5/32 would be seen as the same format of .all projects.
I have never used a Mac so don’t know any of the differences. But on PC it worked…VST’s .all projects seen & opened by SX3, ‘saved as’ from within SX3 to .cpr …which by the way, and I don’t know if this makes a difference, but were your VST 5 projects created on a Mac as well?
Aha - where I was going wrong was that I was trying to OPEN the projects, rather than IMPORTing the projects. Steinberg support pointed that out to me, very quickly I must say.
Thanks Sync for your help in making me persevere.
DOH! Well, glad you got it sorted and others who may be struggling to do this can read your problem & solution. Luckily, my friend sent me exact step by step instructions on how to do it at that time.