Why is this WMI query hanging on the second time it's called?

Question

The following WMI query throws an exception at serverProtocolsManagement.Get() when sqlHost is an invalid server name (as expected. However, if I try to invoke this code again with the same invalid parameter, the ManagementScope constructor hangs indefinitely (never returns or throws an error, just hangs). Is there a reasonable explanation for this?

try {

        ManagementScope managementScope = new ManagementScope(@"\\" + sqlHost + @"\root\Microsoft\SqlServer\ComputerManagement");
        using (ManagementClass serverProtocolsManagement = new ManagementClass(managementScope, new ManagementPath("ServerNetworkProtocol"), null)) {

            serverProtocolsManagement.Get();

            using (ManagementObjectCollection protocols = serverProtocolsManagement.GetInstances()) {
                foreach (ManagementObject protocol in protocols ) {
                    protocol.Get();

                    if ((string)protocol.GetPropertyValue("ProtocolName") == "Tcp" &&
                        (string)protocol.GetPropertyValue("InstanceName") == sqlInstanceName) {

                        protocol.InvokeMethod("SetEnable", null);
                    }
                }
            }
        }
    } catch (COMException ex) {
        MessageBox.Show(ex.ToString());
    }

Edit:

I've tried messing around with different timeout options (by passing a ConnectionOptions object to the ManagementScope constructor), but to no avail.

Edit #2:

I don't know why I didn't think of this (although it still shouldn't be a problem): I was calling this code from the Immediate Window in VS while debugging. There must have been some sort of threading issue, because once I linked this code to a Windows Forms button, everything worked just fine. Thanks for the help!!

Answer 1

Do you have the same problem when you use the ManagementClass constructor (with the string scope instead of the ManagementScope object)?

(therefor skipping the whole ManagementScope step)

Answer 2

Apparently running WMI queries from the Immediate Window while debugging is a no-no. Executing the query as a result of a button press instead fixed the problem.