dappa1
Slugbaby
 
I went back to X1 and it was in there under revert!!!

I doubt X1 would recognize a SPLAT file, so it probably opened the last X1 with that project name.

I didn't work in X1 but I worked in SPLAT I initially went back into SPLAT - Revert nothing. Opened X1 and all the edits and changes I made in SPLAT was in X1

I seriously hope you are not bouncing back and forth between versions and saving the original project(s) in both versions.
 
You should have retained a totally pure copy of the original and only AFTER doing a new Save As version experimenting with all of this.
 
If you are reopening the original file in multiple versions and doing crud to it then just saving under the original name... well that seems like a recipe for corruption.
 
Just pointing that out in case that's what you're doing.
 
Seriously... at this point just spend some time exporting and migrating into a new project. It's the only way to be sure.

Beepster I hear your warning but old features on old songs will only transport from old file to old files because of the plug ins that we used to use and them not transferring from 32bit to 64bit.

There may be others, but Aux Tracks/Patchpoints would have to confuse the BeHayZeus out of X-series versions.

dappa1
Beepster I hear your warning but old features on old songs will only transport from old file to old files because of the plug ins that we used to use and them not transferring from 32bit to 64bit.

What I mean is (and noted upthread in my ramblings) is export the individual tracks with the problematic plugs engaged (if they are in a specific signal chain then you'd want to include any other plugs so as not to screw up any of the chain's interactive effects on the resulting audio). Then bring that wave export into the newer version and proceed from there.
 
Or, again as noted above, just take the raw audio from the old project and figure out a way to duplicate the sound using the newer plug versions.
 
All a PITA fershure but if you can't get the project working as desired then you gotta do it.
 
I generally just finish old projects in the version they were created in (except for projects created in X3 or later). Fortunately I don't really have any important old projects that are incomplete.

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.

I like to go through unfinished projects and as I become more competent with Sonar SPLAT I feel its worth going back and finishing some projects if not trying to finish all of them. It's also good practice and development so sometimes I go back to old files to listen to how I have progressed or not as the case maybe

This could go on and on as it is an apparent fundamental issue with Sonar (cross version project incompatability/corruption).

Old projects are best finished in the original version they were made in. This is why I'm installing every Sonar version I own on my new system. If that doesn't work then I'll have to keep the old computer to finish them instead of selling it.

Is it even worth trying to sell an XP or Windows 7 laptop these days?

I have never had a problem opening an old project in a new Sonar version. If the old project can't find old plugins then it notes it and opens without them. I have projects going back to wrk files. 
 
As far as going back and forth between old and new versions I don't do that. I note in the file name on occasion which version it was saved under. This is just a way to know at a glance what is what.
 
Some odd things were mentioned as to how people save projects. 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.