B4X:
			
		
		
		Sub Process_Globals
    Public Serial1 As Serial
    Dim bc As ByteConverter
End Sub
Private Sub AppStart
    Serial1.Initialize(115200)
    Delay(2000)
    Log(CRLF, "AppStart")
    BugTest
End Sub
Sub BugTest
    Dim i As ULong
    For i = 0x1FFFFFF To 0xFFFFFFFF - 1
        Log(bc.HexFromBytes(bc.ULongsToBytes(Array As ULong(i))))
    Next
End Sub
	Works ?
Or
			
				B4X:
			
		
		
		Sub BugTest
    Dim i As ULong
    For i = 0 To 0xFFFFFFFF - 1
        Log(bc.HexFromBytes(bc.ULongsToBytes(Array As ULong(i))))
    Next
End Sub