bitflipper

Slugbaby
I've had this happen before.
For me, (after a crash) if I try to re-open the project from the "recently opened projects" list under FILE, i get the not-updated project.  However, if I select OPEN and go to the project file itself, it opens the most-recently saved version (can be validated by finding the 'modified date' field).
Seems to be related to the link in the dropdown not getting a chance to update itself due to the crash.

^^^This. Updating the Recent Files entry in the registry is apparently one of the last things SONAR does before it shuts down. Consequently, if you crash while working on a new project it won't show up on the list, even though it's intact on disk. I don't use versioning, but I would imagine the same principle applies.

These message are key above.  If you're clicking 'save' every few seconds, those saves are committed to disk and you should be able to retrieve them.  Versioning or using 'save as' is fine, but using 'save' is just as reliable.
 
As above, the latest version may not be listed in Sonar's drop down box after  abnormal app termination, so you may have to open the latest version manually by checking the 'modified' file date and time. 
 
The only exceptions to this I can think of are if Sonar crashes while you're clicking save, if you're clicking save while audio is still currently rendering or if Sonar has become unstable to the point where a "save" operation isn't completing and a few seconds later, you realize the app has crashed.  But whether you're using "save as" or "save" in those circumstances, I think you'd still have issues.

John
I have been using the independent folder method meaning each project has its own folder. Within that folder I will save various versions of a project. On occasion if I start the same project but with a fundamentally different approach I will create a new folder for it with a new name by adding 2 to the folder name.
 
The idea here is that Sonar and Windows will work well with some very basic file management on the users part. 

I do the same thing for the most part. Some projects have over 50 versions. Sometimes they're opened and saved in newer Sonar versions and then opened and saved in previous versions. Over the course of this things can start going south. It doesn't happen so often but it does happen.
 
The biggest issue for me on this front is opening old projects with Dimension where Dimension no longer works for no reason and I have to insert a new Dimension. Other soft synths don't do this but for me Dimension is notorious so I've learned to freeze before saving.

soens
 
...The biggest issue for me on this front is opening old projects with Dimension where Dimension no longer works for no reason and I have to insert a new Dimension. Other soft synths don't do this but for me Dimension is notorious so I've learned to freeze before saving.

Not to go too OT, but is it possible the older projects have the DXi version of Dimension while your current install uses the VST version instead?   I had that happen some years ago when that transition took place.
 

no software is ever fail safe but you know, I consider myself very lucky.
I have little to no problems in the past couple years. sure I have an occasional WTH happened moment,
but I do consider myself to be very lucky and not have projects that wont open (even as far back as X1 and 8.5)
 
I've seen others here with problems and its real, it happens but like I said, I've been fortunate.
not that this helps or anything