I ran into this problem, too. I thought it might be defective apps, but I simply had too many apps/watch faces loaded onto the watch. The RAM widget is helpful in knowing when the limit is about to be reached.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I ran into this problem, too. I thought it might be defective apps, but I simply had too many apps/watch faces loaded onto the watch. The RAM widget is helpful in knowing when the limit is about to be reached.