offset function not populating - run time 1004 error

HR1 is a defined file path to spreadsheet, HR is the name of the Userform, Initials is the name of the textbox within HR.

I am attempting to move down column C if C4 is not empty until I find the last full cell then move down to the empty one below it however I keep getting an error on the last row of the code. Can anyone tell me what I am doing wrong as it's driving me crazy?

Error message is "Application-defined or object-defined error", still trying to understand these error messages.

    ElseIf HR1.Range("C4") <> "" Then
    
       HR1.Range("C4").Select
            Selection.End(xlDown).Select
                ActiveCell.Offset(1, 0).Value = HR.Initials.Value & "001"

This is the full code if it helps

Private Sub CommandButton1_Click()

HR.Birth.Text = Format(SetUp.PSD.Text, "d mm yyyy")
HR.NI.Text = Format(HR.NI.Text, "## ## ## ## #")
HR.Sort.Text = Format(HR.Sort.Text, "##-##-##")
HR.Salary.Text = Format(HR.Salary.Text, "£0.00")

    '   SPath needs to be changed to the filepath for the main computer computer
    
    '   HR Database Path
Dim FPath As Workbook
Dim SUPath As Worksheet
Set FPath = Workbooks.Open("C:\Users\Scott\Documents\CMC\Database.xlsm")
Set HR1 = FPath.Worksheets("HR")

Application.ScreenUpdating = False

If HR1.Range("C4") = "" Then
    HR1.Range("C4").Value = HR.Initials.Value & "001"
    
HR1.Range("D4").Value = HR.Job.Text
HR1.Range("F4").Value = HR.Birth.Text
HR1.Range("G4").Value = HR.Salutation.Text
HR1.Range("H4").Value = HR.Forename.Text
HR1.Range("I4").Value = HR.MiddleName.Text
HR1.Range("J4").Value = HR.Surname.Text
HR1.Range("K4").Value = HR.House.Text
HR1.Range("L4").Value = HR.Street.Text
HR1.Range("M4").Value = HR.Town.Text
HR1.Range("N4").Value = HR.County.Text
HR1.Range("O4").Value = HR.PostCode.Text
HR1.Range("P4").Value = HR.Tel.Text
HR1.Range("Q4").Value = HR.EmCon.Text
HR1.Range("R4").Value = HR.Rel.Text
HR1.Range("S4").Value = HR.EmConTel.Text
HR1.Range("T4").Value = HR.NI.Text
HR1.Range("U4").Value = HR.Tax.Text
HR1.Range("V4").Value = HR.Bank.Text
HR1.Range("W4").Value = HR.Sort.Text
HR1.Range("X4").Value = HR.ACC.Text
HR1.Range("Y4").Value = HR.Salary.Text

    ElseIf HR1.Range("C4") <> "" Then
    
       HR1.Range("C4").Select
            Selection.End(xlDown).Select
                ActiveCell.Offset(1, 0).Value = HR.Initials.Value & "001"
            
            
ActiveCell.Offset(0, 1).Value = HR.Job.Text
ActiveCell.Offset(0, 3).Value = HR.Birth.Text
ActiveCell.Offset(0, 4).Value = HR.Salutation.Text
ActiveCell.Offset(0, 5).Value = HR.Forename.Text
ActiveCell.Offset(0, 6).Value = HR.MiddleName.Text
ActiveCell.Offset(0, 7).Value = HR.Surname.Text
ActiveCell.Offset(0, 8).Value = HR.House.Text
ActiveCell.Offset(0, 9).Value = HR.Street.Text
ActiveCell.Offset(0, 10).Value = HR.Town.Text
ActiveCell.Offset(0, 11).Value = HR.County.Text
ActiveCell.Offset(0, 12).Value = HR.PostCode.Text
ActiveCell.Offset(0, 13).Value = HR.Tel.Text
ActiveCell.Offset(0, 14).Value = HR.EmCon.Text
ActiveCell.Offset(0, 15).Value = HR.Rel.Text
ActiveCell.Offset(0, 16).Value = HR.EmConTel.Text
ActiveCell.Offset(0, 17).Value = HR.NI.Text
ActiveCell.Offset(0, 18).Value = HR.Tax.Text
ActiveCell.Offset(0, 19).Value = HR.Bank.Text
ActiveCell.Offset(0, 20).Value = HR.Sort.Text
ActiveCell.Offset(0, 21).Value = HR.ACC.Text
ActiveCell.Offset(0, 22).Value = HR.Salary.Text
    End If
            
HR.Hide
FPath.Save
FPath.Close

Application.ScreenUpdating = True

End Sub

yes, header rows in row 3, data input from row 4 downwards. Want to find the last row with data (below row 4) and insert data below it.

I tried range ("C:C"),xlup but that didn't work either

You the man Norie, cheers