Application-defined or object-defined error for if block

I have written the below piece of code in VBA that basically checks if the value in cell B24 is positive and if positive it iterates through a for-loop for 50 times where X0 and sqrt are repeatedly updated.

However when I debug the code it throws an error

'Run-time error '1004'
  Application-defined or object-defined error.

I checked the syntax, it looks fine but the error keeps popping. How to resolve this issue? Help pls

Sub forloopCalc()

Dim X0, sqrt As Integer
Dim sheetName As String
    sheetName = "Sheet1"
    Dim WSD As Worksheet
    Set WSD = Worksheets(sheetName)
    

If (Cells(B, 24).Value > 0) Then
    X0 = 5.96046447753906E-08
    sqrt = 0.000244140625
    For i = 0 To 50
        If ((X0 - Cells(B, 24).Value) < 0) Then
            X0 = X0 * 4
            sqrt = sqrt * 2
        Exit For
        End If
    Next i
End If

WSD.Cells(P, 24).Value = X0
WSD.Cells(R, 24).Value = sqrt
     

End Sub