nested aggr not allowed

[Qlikuser09]

=Sum(if(Aggr(Min(Month([Access Date])), [UserID])= Month(AddMonths(Max(Date),-1)),1,0))

I'm trying to get the count/Sum of the above-mentioned function but it throws me an error

[stevejoyce]

Is your max date supposed to be a global maximum date?  Can you try 

$(=Month(AddMonths(Max(Date),-1)))