In the preferences section of RB and in the Audio tab there is a setting for the "Audio Temp Directory". My RB and BIAB installation is on my I drive, but my Audio Temp Directory setting is C:\Users\1\AppData\Local\Temp\. Perhaps if you looked at your setting, you might want to experiment with yours and see if changing the temp directory to a drive with more space - and preferably a fast SSD - helps with your problem. Just a thought.