C#: AppDomain UnhandledException
===

Im new in appdomain concept. Here's my questions:
1. Is unloading the appdomain when unhandledException trigger is proper way of handling it?
2. Is it best practice that everytime I made a call to my appdomain i have to place it inside trycatch so whatever happens along the invocation I'm going to unload to avoid crashing my main domain?

I have my parent app domain then I created my child app domain named SandBox2. 

            AppDomain sandbox2 = AppDomain.CreateDomain("SandBox2");
            UpdateLog(string.Format("Created AppDomain {0}", sandbox2.FriendlyName));
            try
            {
                sandbox2.ExecuteAssembly(x.ToString()); //along here null exception was triggered
            }
            catch (Exception)
            {
                AppDomain.Unload(sandbox2);
            }

Thank you