im using spritebank plugin to save my sprite pos, angle, vars...
i exported the json from all this to a file that gets loaded when start of layout
later on i created a new variable for this family and made a collision event that changed that var, then i got this error (on collision)
because spritebank loaded the json from sprites that didnt have this variable i got this error,
the solution was delete the old json string and save with the new objects
does this make sense?