Webapp quits silently, what to check?

Targets Web
1

Hi Folks,
I have a webapp running ,and after an update it just silently quits with no message whatsoever after a few minutes.
what are the options to find out where it may come from ?
thanks.
pinging @Ricardo_Cruz

2

If it is deployed with Lifeboat, you can check the logs

Screenshot 2026-04-15 at 13.48.49
Screenshot 2026-04-15 at 13.48.49962Ă—626 91.3 KB

If it is deployed with Xojo Cloud you might be able to see something by connecting through SSH and going through the logs folder.

Screenshot 2026-04-15 at 13.51.17
Screenshot 2026-04-15 at 13.51.171444Ă—910 126 KB

3

sorry forgot to detail ! it’s on macos, standalone with no lifeboat.
no message in the console, or i don’t know how to find them…

edit: the only message i get when the app quits :

par défaut 14:03:30.325786+0200 Entering exit handler.
par défaut 14:03:30.325809+0200 Queueing exit procedure onto XPC queue. Any further messages sent will be discarded. activeSendTransactions=0
par défaut 14:03:30.325901+0200 Cancelling XPC connection. Any further reply handler invocations will not retry messages
par défaut 14:03:30.325953+0200 Exiting exit handler.
par défaut 14:03:30.326141+0200 XPC connection invalidated (daemon unloaded/disabled)
erreur 14:03:30.326275+0200 No error handler for XPC error:
4

ok i will try to save some log in the app.closed and app.unhandledexception events and see what’s coming from it. finger crossed.

5

I think it’s time to do a step-by-step run using the debugger…

6

well I used these two events in the web app class:

Function UnhandledException(error As RuntimeException) Handles UnhandledException as Boolean
  // Timestamp + error info
  Var now As DateTime = DateTime.Now
  Var msg As String = now.SQLDateTime + " | Error " + Error.ErrorNumber.ToString + ": " + Error.Message
  
  dim s() as String = error.Stack
  If s <> Nil and ubound(s)>=0 Then
    msg = msg + EndOfLine + "  " + String.FromArray(s, EndOfLine)
  End If
  
  // Print to terminal stdout
  Print(msg)
  
  // Append to error.log next to the executable
  Var logFile As FolderItem = App.ExecutableFile.Parent.Child("error.log")
  Try
    Var bs As BinaryStream = BinaryStream.Open(logFile, True)
    bs.Position = bs.Length
    bs.Write(msg + EndOfLine + EndOfLine)
    bs.Close
  Catch
    Try
      Var tos As TextOutputStream = TextOutputStream.Create(logFile)
      tos.Write(msg + EndOfLine + EndOfLine)
      tos.Close
    Catch
    End Try
  End Try
  
  ' prevent the app to quit
  Return True
  
End Function

and

Sub Closed() Handles Closed
  Var msg As String = DateTime.Now.SQLDateTime + " | App.Close called"
  
  // Trick to get a stack trace
  Try
    Raise New RuntimeException
  Catch e As RuntimeException
    Var s() As String = e.Stack
    If s.Count > 0 Then
      msg = msg + EndOfLine + "  Stack: " + String.FromArray(s, EndOfLine + "  ")
    End If
  End Try
  
  Print(msg)
  
  Var logFile As FolderItem = App.ExecutableFile.Parent.Child("error.log")
  Try
    Var bs As BinaryStream = BinaryStream.Open(logFile, True)
    bs.Position = bs.Length
    bs.Write(msg + EndOfLine + EndOfLine)
    bs.Close
  Catch
    Try
      Var tos As TextOutputStream = TextOutputStream.Create(logFile)
      tos.Write(msg + EndOfLine + EndOfLine)
      tos.Close
    Catch
    End Try
  End Try
End Sub

and this build a error.log file beside the webapp
and it helped me find a nil error in the session app.

hope this may help someone else in the future !

2 Likes