When attempting to upgrade to v6.0, you may see an error message containing the text "The procedure, ImportUIViews, returned errors", for example:

2022-09-18 14:05:39.529 18-Sep-2022 14:05:39.508  (System.Windows.Threading.Dispatcher) *****An exception occurred at 18 September 2022 14:05:39 using version 6.0.1.1
1. Exception of type: SubstituteException - Message: The procedure, ImportUIViews, returned errors
 System.Object:

Server stack trace: 
   at Pentana.Tng.Installer.UpgradeModelBase.Pentana.Tng.Installer.Interfaces.IUpgradeModel.UpdateData()
   at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg)

Exception rethrown at [0]: 
   at Pentana.Tng.AppManager.Plugins.InstanceTaskWork.<>c__DisplayClass8_1.<DoUpgrade>b__2()
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

This is due to a bug in App Manager versions v6.0.1.1 and earlier. 

It is fixed in v6.0.1.2.