An operator Error throws up a menu, a Warning only a flashy header print. In mesh editmode the menus for simple failures got very annoying, like "Already a face" for Fkey on a face. Proposal is to use warning for contextual failures, like: - wrong selection - unsupported combination - wrong modes And use errors for cases you really need user attention, for example when issues are invisble or potentially damaging work. - Memory failures - Files not found List can grow in future :) let's test this for mesh now. I'll tackle this for other ops later after review. (Also changed: loopcut disabled when editmode shows deformed result)