This is my userform and this is my code, when selecting a name from the Player name box I get a runtime error I am unsure how to fix. The debug shows me this line but I cannot figure out why.

I will post a screenshot of my spreadsheet, we are selecting a name, checking the tickboxes to select times from 00:00 through 23:00 and updating availability in columns J to N.

Private Sub UserForm_Initialize()
    Dim ws As Worksheet
    Dim i As Integer
    
    Set ws = ThisWorkbook.Sheets("Round 5")
    
    ' Clear the ComboBox
    cmbPlayers.Clear
    
    ' Populate ComboBox with player names
    For i = 2 To ws.Cells(ws.Rows.Count, 1).End(xlUp).Row
        cmbPlayers.AddItem ws.Cells(i, 1).Value
    Next i
End Sub

Private Sub cmbPlayers_Change()
    Dim ws As Worksheet
    Dim playerName As String
    Dim i As Integer
    Dim timeSlots As Variant
    Dim dayColumns As Variant
    Dim dayIndex As Integer
    Dim j As Integer
    
    Set ws = ThisWorkbook.Sheets("Round 5")
    playerName = cmbPlayers.Value
    
    ' Define the columns for each day
    dayColumns = Array(12, 13, 14, 15, 16) ' Columns L to P (Wednesday to Sunday)
    
    ' Clear all CheckBoxes
    ClearCheckBoxes
    
    ' Find the player row and populate the CheckBoxes
    For i = 2 To ws.Cells(ws.Rows.Count, 1).End(xlUp).Row
        If ws.Cells(i, 1).Value = playerName Then
            For dayIndex = 0 To UBound(dayColumns)
                timeSlots = Split(ws.Cells(i, dayColumns(dayIndex)).Value, ", ")
                For Each timeSlot In timeSlots
                    For j = 0 To 23 ' 24 time slots
                        If Me.Controls("chk" & dayIndex & j).Caption = timeSlot Then
                            Me.Controls("chk" & dayIndex & j).Value = True
                        End If
                    Next j
                Next timeSlot
            Next dayIndex
            Exit For
        End If
    Next i
End Sub

Private Sub ClearCheckBoxes()
    Dim i As Integer
    Dim dayIndex As Integer
    
    For dayIndex = 0 To 4 ' Wednesday to Sunday
        For i = 0 To 23 ' 24 time slots
            Me.Controls("chk" & dayIndex & i).Value = False
        Next i
    Next dayIndex
End Sub

Private Sub btnUpdate_Click()
    Dim ws As Worksheet
    Dim playerName As String
    Dim i As Integer
    Dim timeSlots As String
    Dim dayColumns As Variant
    Dim dayIndex As Integer
    Dim j As Integer
    Dim found As Boolean
    
    Set ws = ThisWorkbook.Sheets("Round 5")
    playerName = cmbPlayers.Value
    found = False
    
    ' Define the columns for each day
    dayColumns = Array(12, 13, 14, 15, 16) ' Columns L to P (Wednesday to Sunday)
    
    ' Find the player row and update the availability times
    For i = 2 To ws.Cells(ws.Rows.Count, 1).End(xlUp).Row
        If ws.Cells(i, 1).Value = playerName Then
            For dayIndex = 0 To UBound(dayColumns)
                timeSlots = ""
                For j = 0 To 23 ' 24 time slots
                    If Me.Controls("chk" & dayIndex & j).Value = True Then
                        If timeSlots <> "" Then
                            timeSlots = timeSlots & ", "
                        End If
                        timeSlots = timeSlots & Me.Controls("chk" & dayIndex & j).Caption
                    End If
                Next j
                ws.Cells(i, dayColumns(dayIndex)).Value = timeSlots
            Next dayIndex
            found = True
            Exit For
        End If
    Next i
    
    If found Then
        MsgBox "Availability updated successfully.", vbInformation
    Else
        MsgBox "Player not found.", vbExclamation
    End If
End Sub

Sub ShowUserForm()
    UserForm1.Show
End Sub