XML VBA Error Catching

When you run the code with invalid latitude and longitude is that what's returned in the responseText of the request?

If it is I would suggest that you check the responseText before you load it into the XLM/DOM document Resp.

Something like this perhaps.

    For Each Site In SiteList

        req.Open "GET", Site.Value, False
        req.send

        ctrr = ctrr + 1
        siteNames = Worksheets("Site List").Cells(ctrr, 2).Value

        If Instr(req.ResponseText, "An error occurred!") Then
            ' code to do something if there's been a problem
        Else
            Resp.LoadXML req.responseText
            ' continue with code to get data
       End If
 
    Next Site