【背景】更新了二开插件，文件服务器就不能上传了，移除二开后还是不正常，清了.net缓存，文件服务器最终检查结果不可用，

【解决方法】

查看事件查看器频繁出现如下报错

Event code: 3005 

Event message: 发生了未经处理的异常。 

Event time: 8/11/2021 11:10:52 AM 

Event time (UTC): 8/11/2021 3:10:52 AM 

Event ID: 82a67e99447045d7b0d6e5e6a4601d43 

Event sequence: 2 

Event occurrence: 1 

Event detail code: 0 

Application information: 

    Application domain: /LM/W3SVC/4/ROOT-1-132731250520738554 

    Trust level: Full 

    Application Virtual Path: / 

    Application Path: C:\Program Files\Sisense\PrismWeb\ 

    Machine name: K3CLOUDAPP 

Process information: 

    Process ID: 2784 

    Process name: w3wp.exe 

    Account name: NT AUTHORITY\NETWORK SERVICE 

Exception information: 

    Exception type: NullReferenceException 

    Exception message: Object reference not set to an instance of an object.

   at Prism.Web.AppServices.Http.Session.ActiveSession.BuildPrincipal(HttpContext context)

   at Prism.Web.Application.PrismWebModule.HandleBeginRequest(Object sender, EventArgs e)

   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Request information: 

    Request URL: http://58.48.81.xx:8081/ 

    Request path: / 

    User host address: 74.120.14.5x

    User:  

    Is authenticated: False 

    Authentication Type:  

    Thread account name: NT AUTHORITY\NETWORK SERVICE 

Thread information: 

    Thread ID: 8 

    Thread account name: NT AUTHORITY\NETWORK SERVICE 

    Is impersonating: False 

    Stack trace:    at Prism.Web.AppServices.Http.Session.ActiveSession.BuildPrincipal(HttpContext context)

   at Prism.Web.Application.PrismWebModule.HandleBeginRequest(Object sender, EventArgs e)

【解决方案】

通过进一步分析报错堆栈，可能是更新二开插件过程中将IIS-default Web Site身份验证篡改了，开启了模拟ASP.net身份验证，禁用后文件服务器恢复正常。

【emoji】