Matt,

My guess is that your lastrow function returns either null or zero when there are no rows matching your criteria, so the resulting range to delete is A2:AQ1; your header row.

I think that a simple MAX function will sort this out. The sub I copied below adds a new variable (lRow) to look at the result of your (lastrow(ActiveSheet) + 1) argument and take the maximum of that figure or 2. Thus, if the lastrow function returns null, then 2 is larger and the resulting range is A2:AQ2. Hope this helps.

Ben

Dim lRow As Long
Set myrange = Range("A1:" & ConvertToCol(LastCol(ActiveSheet)) & lastrow(ActiveSheet))
myrange.AutoFilter
myrange.AutoFilter Field:=12, Criteria1:="=0", _
Operator:=xlOr, Criteria2:="=2E"
lRow = WorksheetFunction.Max(2, lastrow(ActiveSheet) + 1)
Range("A2:aq" & lRow).SpecialCells(xlCellTypeVisible).Delete
myrange.AutoFilter