Out of system stack space
You entered an expression that LotusScript® is unable to evaluate because the expression contains too many elements. For example, an expression consisting of hundreds of values separated by arithmetic operators would cause this error because the result of each individual arithmetic operation has to be saved on the stack until they can all be combined to calculate the value of the expression as a whole, and there isn't enough room on the stack to save them all.
Break the expression up into smaller pieces handled by multiple statements.