I recently configured an existing application to use ClickOnce deployment. All seemed to go well until I tried to run the application, whereupon it threw an exception on a line that had previously been working perfectly:
AppDomain childDomain;
childDomain = AppDomain.CreateDomain(ChildAppDomainName);
//Following line throws exception
childDomain.UnhandledException += new UnhandledExceptionEventHandler(UnhandledExceptionHandler);
The exception was:
{"Request for the permission of type 'System.Security.Permissions.ReflectionPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed."}
The application was configured to run as FullTrust. To cut a long and frustrating story short, It turned out that the security settings were not being propagated to the child AppDomain. I changed the code to the following:
AppDomain childDomain;
Evidence baseEvidence = AppDomain.CurrentDomain.Evidence;
Evidence childEvidence = new Evidence(baseEvidence);
childDomain = AppDomain.CreateDomain(ChildAppDomainName, childEvidence, AppDomain.CurrentDomain.SetupInformation);
This allowed the child AppDomain to inherit the settings from the parent domain and everything worked as expected once more.
