Thanks Chris B. I use the word 'work' in a loose sense. I am already aware that you correctly advise against using the beta for 'real work'. I'm talking about giving the beta a runthrough on a typical exercise - multiple layers, lots of edits, files being added, exporting to an external disk etc. The crash hasn't happened if the number of edits is low, so the only observable fact is the crash happens when a significant number of edits have been made, and I attempt to export as a psd. That's all I have at the moment.