I'm having a serious problem where Sonar refuses to save, claiming the audio folder to be read-only (which it is not as I can manually write to the folder).
 
Hence, I first posted in the computer forum (see post here), but this may well be some Sonar quirk I haven't faced before.
 
This came out of the blue (no OS changes, updates, etc.) since last recording to the project ...

I can imagine Windows could play such a trick. Have you tried running as administrator or saving under a new name?

Has this just started to happen and have you installed updates to Windows? 
 
I would try running Sonar as administrator as a good first test.

does autosave work?

no. saving in that particular location did not work anymore at all ...
 
FYI, this so far happened in only one project. Save As to a new directory fixed it, but none of the attempts to fix the original project in win10 worked ... did a number of disk and registry checks afterwards. all negative ... let's hope this does not return ...

I had this *exact* same issue. I know this looks like a Windows issue, but I don't believe it is. I tried everything that I could think of along with all the suggestions but nothing worked.

One question. Does your audio folder have a large number of files (or large file sizes? I'm trying to look for a common circumstance

Here's a link to my post in this:
http://forum.cakewalk.com/m/tm.aspx?m=3563648

VariousArtist
I had this *exact* same issue. I know this looks like a Windows issue, but I don't believe it is. I tried everything that I could think of along with all the suggestions but nothing worked.

One question. Does your audio folder have a large number of files (or large file sizes? I'm trying to look for a common circumstance

Here's a link to my post in this:
http://forum.cakewalk.com/m/tm.aspx?m=3563648

No. Not many files. I had actually shrunk the number of files down using Save As about a month before ... file size is also not enourmous. it's a 5 min song at 96 kHz so bounced synth stereo tracks are in the range of 150MB ...

VariousArtist
Here's a link to my post in this:
http://forum.cakewalk.com/m/tm.aspx?m=3563648

everything suggested here I had also tried without success

Just to rule out anything else that's not Sonar related.

Did you do any major hardware upgrade relating to your hard drives, or reinstall Windows, or upgrade Windows, or change user accounts, or change the role of your user account?

My guess is your answer is no, but I just want to see if we also have that in common.

This popped up the other day on my DAW. Sorry but I'm not very methodical on trouble-shooting...I either changed the file name to something shorter or took out a hypen or some other character and it saved. I haven't seen the problem again. But it was an unexpected and never-seen-before error.