Sonar keeps crashing on Save

It's now crashing on every/any save, and I have a deadline approaching rather quickly. Help much sought and much appreciated!

I just opened a different project, and that saves fine, no errors or freezing.
Using the same old synths and plugins I usually use, so that lessens the chance of it being them...

I think some of the audio files I've used are aiff, but audio folder shows them as wav (so obvs Sonar resaved/converted). Can't think of what it is other than Sonar just not liking the project, which is ironic as it's one of my better ones.

I have 82 gb free.

But Sonar just gave me a error message about memory.

Really don't get whats going on. Have made bigger projects than this.

More likely a windows issue like a problem with the hard drive.

82 Gigs is your Hard drive not your memory. 
And that sounds full by today's standards. Audio really likes a nice clean 7200 rpm drive with no fragments and 50% headroom. . 
Back everything up to a external drive before you do anything else. 

You should put your computer specs in your signature, it makes it easier to figure stuff out when we know what we are dealing with. 

Are you backing up to a second drive? If so those versions would return you to a un corrupted state, That is why we back up to a second drive as we work.

Having other saved versions on the same hard drive could mean loosing everything at once.  

Did you try my suggestion yet?

You haven't listed any hard drives in your sig - this could be important!

bitflipper, I tried your suggestion, and it gave me a worse crash, first it windows start copying audio files as I saved and then it crashed, then i got Sonar message *"Error. Out of memeroy" or something. Then I got some kind of **Miscrosoft Visual C++ Runtime Library error/message (though I cannot see what it says, the box is blank).

*What is this? Why does this happen?
**Any clue what/why this is?


And again lastly, any idea why the project file is so huge in comparison to usual?!?!?!

I said I use a backup drive.

My hard drive is 5-600GB and I have 82GB left.
In my project folders there are the 'audio' folders too.where the audio is stored. I think currently 'save audio with project' is ticked.

This problem I've only had with this track, and  made this track using a new template I created, so wondering if that could be a problem?

I should have been more clear, sorry.

Close SONAR and any other open programs. In Windows Explorer, navigate to the folder above your project folder. Right-click on the folder and select "Copy". Then click in the white space between icons and select "Paste". You'll get a copy of the project folder with a name like "Copy of {Project_Name}".

Open SONAR and open the project in the "Copy of ____" folder. 

One of these things is going to happen:

1. The copy/paste will fail because there is a corrupt file in your project that Windows cannot read. Explorer should tell you the name of the bad file, in which case you should rename it to "Corrupt File Do Not Delete". Don't delete it until you've had a chance to back everything up and run a disk repair.

2. The copy/paste will complete and the newly-copied project will open and save with no errors, in which case you rename the original project "Corrupt Project Do Not Delete" and carry on. After you've backed up and run a disk repair, you can delete it.

3. The copied project will fail to open or save, in which case you've got serious disk corruption, either a corrupt wave file (hopefully, because you can figure out which one it is and delete it), or a corrupt project file. If the latter, you're pretty much screwed unless you want to start a new project and import each file one-by-one.