To close a temporary file you’re no longer using, select the file in the Waveform list and click Close File. (The currently active waveform can’t be closed this way, however.)

To clear Undo items for a file, select the file in the Waveform list. The Undo History list displays the actions that are currently being retained on your system and the amount of hard drive space each instance consumes. Select an item and click Clear Undo(s). All items at the selected level and below are removed.

To stop any action in progress, such as the application of an effect or any other edit, click Cancel Last Operation. This option is useful only if the dialog box automatically appeared because you ran out of storage space.

If Adobe Audition crashes, there may be a temp file (audxxxx.tmp) in your temporary folder that you should manually delete.