Internal server error (500) when clicking edit extension

[gehri]

Hi,
when i click edit extension i get this error:

System.InvalidOperationException: La sequenza non contiene elementi
in System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
in ConfigurationManagementModel.CfgStringsEnum.GetValue()
in System.Lazy`1.CreateValue()
in System.Lazy`1.LazyInitValue()
in ManagementConsoleJS.Services.Adapters.CmmAdapter.SerializeCmmEnum(ICfgEnum value)
in ManagementConsoleJS.Services.Adapters.CmmAdapter.SerializeCmmProperty(String wpPropName, ICfgProperty prop)
in ManagementConsoleJS.Services.Adapters.CmmAdapter.SerializeCmmItem(ICfgItem item, Boolean isTopLevel)
in System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
in System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
in System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
in ManagementConsoleJS.Services.Adapters.CmmAdapter.SerializeCmmProperty(String wpPropName, ICfgProperty prop)
in ManagementConsoleJS.Services.Adapters.CmmAdapter.SerializeCmmItem(ICfgItem item, Boolean isTopLevel)
in ManagementConsoleJS.Services.EditorServiceExtensions.ProcessActiveObjectRegistration(IEditorService editorService, ICfgItem obj, PropertyFilter filter)
in Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionFilterAsync>d__28.MoveNext()
--- Fine traccia dello stack da posizione precedente dove è stata generata l'eccezione ---
in Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeAsync>d__18.MoveNext()
--- Fine traccia dello stack da posizione precedente dove è stata generata l'eccezione ---
in System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
in System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
in Microsoft.AspNetCore.Builder.RouterMiddleware.<Invoke>d__4.MoveNext()
--- Fine traccia dello stack da posizione precedente dove è stata generata l'eccezione ---
in System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
in System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
in ManagementConsoleJS.Middleware.ExceptionWrapperMiddleware.<Invoke>d__3.MoveNext()

What can i do?