Procedure breaks/stops at Application.WorksheetFunction.Average()

Question

Edition Windows 10 Pro

Version 21H2
OS build 19044.1586
Excel 2007, VBA: Retail 6.5.1057 - Forms3: 12.0.6723.500

The concern:

Sheets("SUMMARY").Cells(Rows.Count, 3).End(xlUp).Offset(1, 0) = _
                        Application.WorksheetFunction.Average(irng)

When the above code is used 'manually' (F5), in the module below, it works. However, when the 'timer' triggers/engages, the procedure breaks/stops dead at that line.

I've spread the code over multiple procedures in an effort to troubleshoot; didn't help my cause.

Option Explicit
Public RunWhen As Double
Public Const cRunWhat = "kcal"  ' the name of the procedure to run
Sub StartTimer()
RunWhen = TimeSerial(23, 45, 0)
Application.OnTime EarliestTime:=RunWhen, Procedure:=cRunWhat, _
    Schedule:=True
End Sub

Private Sub kcal()
Sheets("SUMMARY").Cells(Rows.Count, 1).End(xlUp).Offset(1, 0).Value = Date
Sheets("SUMMARY").Cells(Rows.Count, 2).End(xlUp).Offset(1, 0).Value = Sheets("TODAY_(24hr)").Range("E40").Value

kcal2
End Sub

Sub kcal2()
Dim i As String
Dim irng As Range
i = Sheets("SUMMARY").Cells(Rows.Count, 2).End(xlUp).Address
Set irng = Range("B2:" & i)

Sheets("SUMMARY").Cells(Rows.Count, 3).End(xlUp).Offset(1, 0) = Application.WorksheetFunction.Average(irng)
 
ActiveWorkbook.SaveCopyAs Filename:=ActiveWorkbook.Path & "\Back_Up\Bak-Up_" & Format(Now, "yyyymmdd") & "_m" & ActiveWorkbook.Name

StartTimer

End Sub

Answer 1

The actual fix to the original 'posted\broken' code is to change --

Set irng = Range("B2:" & i)

-- To --

 Set irng = Sheets("SUMMARY").Range("B2:" & i)    

While\When using the erroneous line

Set irng = Range("B2:" & i)    

if and when the ActiveSheet --was any other sheet than

Sheets("SUMMARY")    

the project/procedure would try and apply

Sheets("SUMMARY").Cells(Rows.Count, 3).End(xlUp).Offset(1, 0) = Application.WorksheetFunction.Average(irng)   

to that ActiveSheet, and not to

Sheets("SUMMARY")    

which the ActiveSheet, when not Sheets("SUMMARY"), did not have data in the specified [ irng ] that [ Average() ] could process. <-- That is why the code failed. By making the change to

Set irng = Sheets("SUMMARY").Range("B2:" & i)    

this is specifying 'exactly' which sheet [ irng ] should be [ Set ] to. Something that

Set irng = Range("B2:" & i)    

did not accomplish.

Thank you all for your contributions.