My application showing error after installing some packages from NuGet

Server Error in '/' Application. The following errors occurred while attempting to load the app. - No assembly found containing an OwinStartupAttribute. - No assembly found containing a Startup or [AssemblyName].Startup class. To disable OWIN startup discovery, add the appSetting owin:AutomaticAppStartup with a value of "false" in your web.config. To specify the OWIN startup Assembly, Class, or Method, add the appSetting owin:AppStartup with the fully qualified startup class or configuration method name in your web.config. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.EntryPointNotFoundException: The following errors occurred while attempting to load the app. - No assembly found containing an OwinStartupAttribute. - No assembly found containing a Startup or ...