Hi. I've had this error a couple of times, and can't figure it out.
I write a macro and when running it I get "Code Execution has been
interupted" and when I debug it's on random lines...

Today i've wrote a macro, which I'll attach at the bottom. The macro worked
great, but since I don't need to watch it running and it'd be quicker I
turned screen updating off. Now it errors.

The error comes up mostly on "If n = 0 Then" and looking at it n = 1 at that
point, but half the time it will be a random line of code that seemingly
looks fine to me...

dat is yesterday's date from the workbook, so it deletes all lines with
previous date, and if column 4 is Z then its not an appointment and wants
deleting. day1 and day2 are files with a name based on today's date, so are
variable.

As far as I can tell theres nothing wrong with this code. I certainly get
none of the normal errors when I write something shoddy, just the interuption
thing... i'm not pressing any keys or anything while it runs it just seems to
interupt itself for no reason I can see...

Sub open_reports()
Dim day1 As Variant
Dim day2 As Variant
Dim i As Variant
Dim dat As Variant
Dim n As Variant

Application.ScreenUpdating = False

Sheets("Calc").Select

day1 = Range("B19").Value
day2 = Range("C19").Value
dat = Range("F2").Value

Workbooks.Open Filename:= _
day1
Sheets("diary").Select
Windows("Appointments Booked.xls").Activate
Workbooks.Open Filename:= _
day2
Sheets("diary").Select
Cells.Select
Selection.Copy
Windows("Appointments Booked.xls").Activate
Sheets("Sheet3").Select
Range("A1").Select
ActiveSheet.Paste
Windows("Appointments Booked.xls").Activate
Range("B2").Select

i = 2

Do Until i = 50000

n = 0

If Cells(i, 4) = "Z" Then
n = 1
Else
End If

If Cells(i, 5) < dat Then
n = 1
Else
End If

If n = 1 Then Rows(i).Delete
If n = 0 Then i = i + 1


Loop
End Sub