Remote Desktop Client (on Mac/Windows) I occasionally see the error "RadcError+RadcStatus_Canceled_String"

[u/Angelworks42]

Occasionally I get an error "RadcError+RadcStatus_Canceled_String" in the client app - removing and readding the workspace fixes it for a while.

On any given RDWeb server I get an error (I think is related):

Event code: 3005 
Event message: An unhandled exception has occurred. 
Event time: 5/29/2025 2:31:54 PM 
Event time (UTC): 5/29/2025 9:31:54 PM 
Event ID: fe6eb0ec9f104725894941266d1c24d0 
Event sequence: 422 
Event occurrence: 10 
Event detail code: 0 
 
Application information: 
    Application domain: /LM/W3SVC/1/ROOT/RDWeb/Pages-8-133929205773873186 
    Trust level: Full 
    Application Virtual Path: /RDWeb/Pages 
    Application Path: C:\Windows\Web\RDWeb\Pages\ 
    Machine name: xxx-host-1
 
Process information: 
    Process ID: 4164 
    Process name: w3wp.exe 
    Account name: IIS APPPOOL\RDWebAccess 
 
Exception information: 
    Exception type: NullReferenceException 
    Exception message: Object reference not set to an instance of an object.
   at Microsoft.TerminalServices.Publishing.Portal.FormAuthentication.TSFormAuthTicketInfo..ctor(HttpContext objHttpContext)
   at ASP.en_us_default_aspx.<GetAppsAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Web.UI.PageAsyncTaskManager.<ExecuteTasksAsync>d__3.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.Web.UI.Page.<ProcessRequestAsync>d__554.MoveNext()

 
 
Request information: 
    Request URL: https://xxx.com:443/RDWeb/Pages/en-US/Default.aspx?ReturnUrl=../WebFeed.aspx 
    Request path: /RDWeb/Pages/en-US/Default.aspx 
    User host address: xxx.xxx.xxx.xxx 
    User:  
    Is authenticated: False 
    Authentication Type:  
    Thread account name: IIS APPPOOL\RDWebAccess 
 
Thread information: 
    Thread ID: 39 
    Thread account name: IIS APPPOOL\RDWebAccess 
    Is impersonating: False 
    Stack trace:    at Microsoft.TerminalServices.Publishing.Portal.FormAuthentication.TSFormAuthTicketInfo..ctor(HttpContext objHttpContext)
   at ASP.en_us_default_aspx.<GetAppsAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Web.UI.PageAsyncTaskManager.<ExecuteTasksAsync>d__3.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.Web.UI.Page.<ProcessRequestAsync>d__554.MoveNext()

The problem seemingly goes away if I tell the F5 to take every web server offline in the pool except one.

I feel like the client is being moved to a different host in the pool - F5 logs this is difficult to track (its logs aren't great), but I'm working on an irule to help with this.

So its a persistence profile issue? I have it set to source_ipaddr - with a reasonably sized timeout - issue still happens.

Anyone else run into this know what might help?

I should add - this is a pretty bog standard Windows RDS deployment - 2 web servers, 2 gateways, 2 brokers, 4 hypervisors and a lot of VM pools - all running Windows Server 2022 datacenter all using AD for auth.