安装了 plugin.media library 后出现了这个错误。
Severity Code Description Project File Line Suppression State Error The "GenerateJavaStubs" task failed unexpectedly. System.InvalidOperationException: There can be only one type with an [Application] attribute; found: ,at Xamarin.Android.Tasks.ManifestDocument.CreateApplicationElement(XElement manifest, String applicationClass, List`1 subclasses, List`1 selectedWhitelistAssemblies)at Xamarin.Android.Tasks.ManifestDocument.Merge(List`1 subclasses, List`1 selectedWhitelistAssemblies, String applicationClass, Boolean embed, String bundledWearApplicationName, IEnumerable`1 mergedManifestDocuments)at Xamarin.Android.Tasks.GenerateJavaStubs.Run(DirectoryAssemblyResolver res)at Xamarin.Android.Tasks.GenerateJavaStubs.Execute()at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext() XamarinForms.QbChat.Android