C# mono xsp4错误500 ArgumentNullException

我在mac上安装了mono版本3.8。我使用xsp4来运行我的asp.net web应用程序。然后我得到了下面的错误500。请帮帮我

System.ArgumentNullException

Argument cannot be null.

Parameter name: type

Description: HTTP 500.Error processing request.

Details: Non-web exception. Exception origin (name of application or object): mscorlib.

Exception stack trace:
  at System.Activator.CheckType (System.Type type) [0x00000] in <filename unknown>:0 
  at System.Activator.CreateInstance (System.Type type, Boolean nonPublic) [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.LinqDataSourceView+<ExecuteSelect>c__Iterator1.MoveNext () [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.ListView.CreateItemsWithoutGroups (System.Web.UI.WebControls.ListViewPagedDataSource dataSource, Boolean dataBinding, InsertItemPosition insertPosition, System.Collections.ArrayList keyArray) [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.ListView.CreateChildControls (IEnumerable dataSource, Boolean dataBinding) [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.ListView.PerformDataBinding (IEnumerable data) [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.DataBoundControl.InternalPerformDataBinding (IEnumerable data) [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.DataBoundControl.OnSelect (IEnumerable data) [0x00000] in <filename unknown>:0 
  at System.Web.UI.DataSourceView.Select (System.Web.UI.DataSourceSelectArguments selectArgs, System.Web.UI.DataSourceViewSelectCallback callBack) [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.DataBoundControl.PerformSelect () [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.ListView.PerformSelect () [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.BaseDataBoundControl.DataBind () [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound () [0x00000] in <filename unknown>:0 
  at System.Web.UI.WebControls.ListView.CreateChildControls () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Control.EnsureChildControls () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Control.PreRenderRecursiveInternal () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Control.PreRenderRecursiveInternal () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Control.PreRenderRecursiveInternal () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Control.PreRenderRecursiveInternal () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Control.PreRenderRecursiveInternal () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Page.ProcessLoadComplete () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Page.InternalProcessRequest () [0x00000] in <filename unknown>:0 
  at System.Web.UI.Page.ProcessRequest (System.Web.HttpContext context) [0x00000] in <filename unknown>:0 

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我尝试使用LinqDataSource的对象列表实例。现在是工作了