Hi, I just release 2.9.21. This release fixes a number of crashing bugs, and upgrading is generally recommended. The delay is due to the fact that I had originally hoped to be able to incorporate some more patches, but those turned out not to be of the quality that I'd hoped for; and these really can't wait anymore. Hence. Regards, -- The volume of a pizza of thickness a and radius z can be described by the following formula: pi zz a