What can cause Outlook to change a COM-addin's LoadBehavior to 2 - other than unhandled exceptions?

Question

For some weeks now we have been fighting with an issue where at a small number of customers our Outlook addin gets unloaded and disabled for yet undetermined reasons. By \"d

Answer 1

maybe you are a lockback policy victim. add a bypass key to registry, then it works. modern office versions or vsto creates the key while installation. the effect is: install a modern office too and the affffdin now are also loaded in older office. please take a look

code snippet taken from NetOffice http://netoffice.codeplex.com

public static void RegisterFunction(Type type)
{
            try
            {
                // add codebase value
                Assembly thisAssembly = Assembly.GetAssembly(typeof(ExampleClassicAddin));
                RegistryKey key = Registry.ClassesRoot.CreateSubKey("CLSID\\{" + type.GUID.ToString().ToUpper() + "}\\InprocServer32\\1.0.0.0");
                key.SetValue("CodeBase", thisAssembly.CodeBase);
                key.Close();

                key = Registry.ClassesRoot.CreateSubKey("CLSID\\{" + type.GUID.ToString().ToUpper() + "}\\InprocServer32");
                key.SetValue("CodeBase", thisAssembly.CodeBase);
                key.Close();

                // add bypass key
                // http://support.microsoft.com/kb/948461
                key = Registry.ClassesRoot.CreateSubKey("Interface\\{000C0601-0000-0000-C000-000000000046}");
                string defaultValue = key.GetValue("") as string;
                if (null == defaultValue)
                    key.SetValue("", "Office .NET Framework Lockback Bypass Key");
                key.Close();

                // add addin key
                Registry.ClassesRoot.CreateSubKey(@"CLSID\{" + type.GUID.ToString().ToUpper() + @"}\Programmable");
                Registry.CurrentUser.CreateSubKey(_addinRegistryKey + _prodId);
                RegistryKey rk = Registry.CurrentUser.OpenSubKey(_addinRegistryKey + _prodId, true);
                rk.SetValue("LoadBehavior", Convert.ToInt32(3));
                rk.SetValue("FriendlyName", _addinName);
                rk.SetValue("Description", "NetOffice COMAddinExample with classic UI");
                rk.Close();
            }
            catch (Exception ex)
            {
                string details = string.Format("{1}{1}Details:{1}{1}{0}", ex.Message, Environment.NewLine);
                MessageBox.Show("An error occured." + details, "Register " + _addinName, MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
}