Runtime Error 1004: Hidden Property

[KMacattack]

I am getting a Runtime Error 1004: Unable to set the Hidden property of the Range class

I have a macro that updates a bunch of pivot tables based on selections from data validation dropdowns.
(this works fine)

Based on the users selections I want to hide and unhide various rows.

i do this in two steps:
from the code to update the pivot table:
goes to a function to specify the which rows to hide or unhide (collapse):

Public Sub Collapse()
Sheets("Exhibit").Activate
'Unhide all rows
    UnHide 13, 200
'hide/unhide month 
       'Hides the Months after the month given in Cell A5
        hide 16 + (Month(Sheets("Exhibit").Range("A5"))), 28
    End If
< ... there is more of similar code below ... >       
   End sub

The Unhide and Hide are separate functions.

Sub hide(R1, R2)
'Hides rows R1 to R2 in Exhibit Tab
    ActiveSheet.Rows(R1 & ":" & R2).Hidden = True
End Sub
---------------------------------------------------------
Sub UnHide(R1, R2)
'Unhides Rows R1 to R2 in Exhibit Tab
    ActiveSheet.Rows(R1 & ":" & R2).Hidden = False
End Sub

And when the code gets to the unhide 13,200 function i get that error.

My workbook is unprotected and unlocked: as i found in many other forms that was the problem.

the other thing is that it sometimes works and other times doesn't and i can't pinpoint the situation that makes it happen.

so if anyone has a fix or reason for this please help.

Thank You

Mac

 

[xld]

Is the sheet protected?