從 Net48 遷移到 Net60 期間出現 Microsoft.VisualStudio.ProjectSystem.Query.QueryExecutionException

Question

我正在嘗試將我的項目從 net48 遷移到 net6。 定位到 net60 后，出現 lof 警告：

此外，當我打開項目屬性時，我看到以下錯誤：

Microsoft.VisualStudio.ProjectSystem.Query.QueryExecutionException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.VisualStudio.LanguageServices.CSharp.ProjectSystemShim.EntryPointFinder.FindEntryPoints(INamespaceSymbol symbol)
   at Microsoft.VisualStudio.ProjectSystem.Properties.StartupObjectsEnumGenerator.<GetListedValuesAsync>d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.VisualStudio.ProjectSystem.PropertyPages.PageDynamicEnumProperty.<CreateAdmissibleValuesAsync>d__6.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.ProjectSystem.VS.Query.SupportedValueDataProducer.<CreateSupportedValuesAsync>d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.ProjectSystem.VS.Query.QueryDataFromProviderStateProducerBase`1.<SendRequestAsync>d__0.MoveNext()
   --- End of inner exception stack trace ---
   at Microsoft.VisualStudio.ProjectSystem.Query.QueryExecution.QuerySubscription`1.<RunQueryOnceAsync>d__9.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.ProjectSystem.Query.QueryExecution.QuerySubscription`1.<>c__DisplayClass8_0.<<Start>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.ProjectSystem.VS.Implementation.PropertyPages.Designer.ProjectPropertyDataAccess.Observer.<InitializeAsync>d__10.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Microsoft.VisualStudio.ProjectSystem.VS.Implementation.PropertyPages.Designer.ProjectPropertyDataAccess.Observer.<CreateAsync>d__9.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.ProjectSystem.VS.Implementation.PropertyPages.Designer.ProjectPropertiesEditor.<>c__DisplayClass0_0.<<-ctor>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.ProjectSystem.VS.Implementation.PropertyPages.Designer.AsyncLoadContent.<>c__DisplayClass0_0.<<Initialize>b__0>d.MoveNext()

如何解決？

Answer 1

不知道你是如何開始遷移的，但這個工具很有幫助https://github.com/dotnet/upgrade-assistant

Answer 2

這個錯誤部分與這個錯誤有關，一旦我解決了主要問題，這個錯誤就被修復了。