Familiar error "Audition has reached limit of audio data it can use"

Ok, well I've also been dealing with this issue for a while, and am familiar with the remedies suggested here. They did work for a while but now, I've got one half hour file that I want to append to another half hour file and it's throwing that error. So what would be the reason it's not able to edit a paltry 41,000 KB onto a 73,000 KB file?  And I've only got one file open, the one I'm working on, so I can't close anything. It doesn't make any sense.

In that case, you need to investigate exactly what is on the drive you think has so much space on it! This doesn't happen very often, so there's relatively little information available, but there is a thread about it you can read here (just ignore all the nice things it says about me 😉 ).  The thing to mention directly though is what you have your Auto save recovery data time interval set to in Edit>Preferences>Auto Save. This is generally what fills drives up. The backup settings don't matter so much, because they only relate to session files - but Auto Save saves recovery data for the whole app - and if you are dealing with huge files, it's easy to run out of space, even on a huge drive.The chances are that you can delete most of the stuff that's there, especially if you've been working on long sessions.

The thing is, it's not just the temp files you can see that cause the problems...