Cannot write disk may be full

I searched for this problem, I've had it before and so have others but I found nothing. What do you do when you get this error?
 
Thanks - rev

In some instances, starting/stopping the transport has allowed the file to be saved.

How much spare space do you have on your hard drive? Have you run disk cleanup lately?

This happens to me sometimes if i use an audio program before i launch sonar or if i have sonar loaded then use another player then go back to sonar..so i found if i dont open another audio program i wont get the warning..im also not using the asio driver im using the other ones wwm or mm something or other...this happened in my old cakewalk program also...deleting the aud.ini file before each load worked

Sometimes I get this message too.
In our case it's up to our NAS-Server where the disc sometimes reacts too slow. This is up to a energy saving disc.
If this message appears, it's often the only way to close Sonar and restart it. Because Sonar remembers the problem and locks itself. In our case the reaction time of the disc is the problem after waking up from energy saving.

revnice1
I searched the forum for other posts because this used to be a common problem but I only found my own post.

Try a Google search like "site:forum.cakewalk.com save disk full" and you should get more results
 

I recently had the same message and in my case it had nothing to do with disk space. I had been moving files from a memory stick and at one point I got the message in the OP. Sonar was trying to access the memory stick that was no longer in my USB port. Perhaps in this case it's something similar.

I get it sometimes but it always goes away when I try the action again or use save as.  I think it could be the disk is busy at that instant or something affecting the IO of sonar buts its never been an issue that actually prevented me from continuing 
 

Some times ago I remember this problem being related to the Master Boot Record; MBR, of the disk in question.
Like Long File Names or the file is nested into too many folders. Also a partition drive. 
A corrupted MBR or a virus. Try saving the file to the root of the drive in question.

It's a long time ago, but I seem to recall Sonar of that vintage, or maybe Windows or an interaction of the two having an issue with importing tagged mp3 files that could result in that error. And it turned up as an error once in a while years ago, but other than the mp3 thing I don't think anyone got to the bottom of it. So it's quite possible there's no single cause.

One suggested solution was to delete the Sonar picture cache and let it build a new one.
Another possibility is that the drive isn't reacting quickly enough which might be the case if the audio spooling drive is allowed to go to sleep while Sonar is running and Sonar announces that error if Windiws doesn't rell it the drive is ready within the time frame Sonar expects.
Or that the drive buffers (not the audio buffer) need increasing in preferences.

Here's everything I've gathered so far. Method 10 definitely works but it's a dog!
 
1) Export any audio track as a wave file, then try to Save.
2) Use Save As.
3) Double disk I/O buffers in preferences.
4) Try saving the file to the root of the drive in question in case deep nesting is the problem
5) Delete the picture cache
6) Double "DiskRecBufSize" in Aud.ini (to 512)
7) Consolidate Audio under Tools.
Then go to the Audio folder and delete everything EXCEPT the backup folder.
Open the backup folder and move the saved audio to the Audio folder.
Delete the empty backup folder.

8) Run CheckDisk on SONAR drive ('Disk may be full' is probably not a disk issue though)
9) Reboot
10) Copy all contents to a new file.
For some reason this is not the same as Save As. It's worked for me in the past but it's a long and tedious process
if you have a lot of tracks.
a) Open a new file and save it with a new name. Open the problem file.
b) Drag the source file aside so you can see both.
c) Recreate the source tracks in the destination file and label them all just as they are in the source
d) Now drag copy (Cntrl/drag) all the effects plugs one by one from source file tracks to the corresponding destination tracks
e) Set the volume and pan settings in the destination tracks so they're the same as the source
f) Copy (Cntrl/drag) the audio and MIDI data one track at a time to the prepared destination tracks
g) Add the same synths to the Synth Rack destination file and copy any settings such as drum kit presets, fader settings, articulations, etc
Keep saving the destination file as you work. When you've finished you should have two identical files with identical plugs, settings and synths. I don't know why this works or how it's different to Save As but the new file won't give you the 'Cannot write' error.
The only reason I'm looking for another solution is because method 10 is so long and tedious.

Is it possible you resurrected that file/folder from an archive? Some archiving functions will set the contents to "read only" and I am now wondering if it may be something similar. Have you tried changing the properties on that project folder by unchecking "read only" (project cannot be open to set it)?
 
If you can create and save a new project without issues, I am struggling to believe this is within SONAR.