App Manager can crash on upgrading the client package if you run through the standard sequence and are upgrading from a prior major or minor version.

The error message displayed by App Manager is: 

TngException
Message: Error running background task
  Stack trace:
  at at Pentana.Tng.AppManager.AsyncHelper.<>c__DisplayClass1_2.<RunAsync>b__3()
  **************************************************
  NullReferenceException
  Message: Object reference not set to an instance of an object.
  Stack trace:
  at at Pentana.Tng.AppManager.Common.Helpers.CopyCustomerFiles(DirectoryInfo target,
  DirectoryInfo newFiles, String subDirName)
  at Pentana.Tng.AppManager.Common.Helpers.CopyNewFiles(DirectoryInfo target, DirectoryInfo
  newFiles, String subDirName, Boolean isClickOnce)
  at Pentana.Tng.AppManager.Plugins.ClickOnce.CopyNewClickOnceFiles()
  at Pentana.Tng.AppManager.Plugins.ClickOnce.Update()
  at Pentana.Tng.AppManager.Plugins.ClientViewModel.DoClickOnceUpgrade()
  at Pentana.Tng.AppManager.Plugins.ClientViewModel.<UpgradeExecute>b__27_0()
  at Pentana.Tng.AppManager.AsyncHelper.<>c__DisplayClass1_0.<RunAsync>b__0(Object
  sender, DoWorkEventArgs e)
  at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e)
  at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)

If you quit App Manager and try again the upgrade will run to completion, but the resulting ClickOnce package will have the wrong package name and the user's client install will not auto-update. Instead, Ideagen Internal Audit (Aura) will launch and the user will get the message:

"The request's database version, x.x.x.x is different to the version on the server, 5.4.0.x".

Workaround

If App Manager crashes while upgrading the Client:

• Close App Manager
• Delete the client package folder that has just been created, e.g.
  C:\inetpub\wwwroot\[instance name]\Client\Vision_5_4_0_6
• Restart App Manager
• Retry the upgrade step again

If the above does not work please contact support.