sub of function is niet gedefinieerd

Sub GetCandidates()
 
      For num = 1 To 9
      
          If WorksheetFunction.CountIf(sud.Range("B2:J10"), num) < 9 Then
       
             For Each cell In sud.Range("B2:J10").SpecialCells(xlCellTypeBlanks)
          
              If WorksheetFunction.CountIf(sud.Rows(cell.Row), num) = 0 And _
              WorksheetFunction.CountIf(sud.Columns(cell.Column), num) = 0 And _
              WorksheetFunction.CountIf(sud.Range(qrng(cell.Row, cell.Column)), num) = 0 Then _
                   sol.Cells(cell.Row, cell.Column) = sol.Cells(cell.Row, cell.Column) & num
            
            
            
           Next cell
         
         End If
    
      Next num
    
End Sub
Private Function qrng(r As Integer, c As Integer) As String
    If c < 5 Then
        If r < 5 Then
            qrng = "B24"
        ElseIf r < 8 Then
            qrng = "B57"
        Else
            qrng = "B810"
        End If
    ElseIf c < 8 Then
        If r < 5 Then
            qrng = "E2:G4"
        ElseIf r < 8 Then
            qrng = "E5:G7"
        Else
            qrng = "E8:G10"
        End If
    Else
        If r < 5 Then
            qrng = "H2:J4"
        ElseIf r < 8 Then
            qrng = "H5:J7"
        Else
            qrng = "H8:J10"
        End If
    End If
End Function

Sub solvesingles()


    Dim cel As Range, numadded As Boolean


    For Each cell In sol.Range("B2:J10").SpecialCells(xlTextValues)
    
    If Len(cell.Value) = 1 Then
        
        sud.Cells(cell.Row, cell.Column) = sol.Cells(cell.Row, cell.Column).Value
            numadded = True
            
        
        End If
        
      Next cell
    
    
If WorksheetFunction.CountA(sud.Range("B2:J10")) < 81 Then
        If numadded = True Then
            Call GetCandidates
    
    Else
                Call findhiddensingles
        End If
        End If
                    
End Sub


Sub findhiddensingles()


    'rows
    For r = 2 To 10
        For c = 2 To 10
            hints = sol.Cells(r, c).Value
            If hints <> "" Then
                For i = 1 To Len(hints)
                    num(i) = Mid(hints, i, 1)
                    
                    
                    For c2 = 2 To 10
                        hints2 = sol.Cells(r, c2).Value
                        If hints2 <> "" And c2 <> c And _
                        InStr(hints2, num(i)) > 0 Then notsingle = True
                    Next c2
                    
                        If notsingle = False Then sud.Cells(r, c) = num(i)
                    Next i
                End If
            Next c
        Next r
                              
        'colums next
        
End Sub