Error in expression dze_cleanup

[Carp!]

Hey Survivors!

I'm back with a new error that Google is unable to help me with:

3:53:58 Error in expression <if (DZE_CleanNull) then {
[] spawn server_sp>
3:53:58 Error position: <DZE_CleanNull) then {
[] spawn server_sp>
3:53:58 Error Undefined variable in expression: dze_cleannull

I am unable to even locate where dze_cleannull is. Any thoughts or a place to start with this?