#2579: Added null check when evaluating lists

(cherry picked from commit 08b8180a3f47fd876edb94e91d940c350114473d)
References #2575: Fixed issues with serializing top-most CompositeFilter parameters.  Fixed issue with deserializing ColumnFilter sliders.

(cherry picked from commit 8f5d5a7476beb3161abb79b4b1f9398cf5b72b28)