Error Message
Users with older versions of the .NET framework installed may get the error below when invoking the View/Hide Results commands.
Could not manage results
Exception:
System.MissingMethodException: Method not found: 'System.Collections.Generic.HashSet`1<!!0> System.Linq.Enumerable.ToHashSet(System.Collections.Generic.IEnumerable`1<!!0>)'.
at Lai.Revit.CalcPointsPersistentDisplayManager.DeleteOrphanedViewResultsInfo(Document document)
at Lai.Revit.CalcPointsPersistentDisplayManager.Save(Document document, ViewResultsInfo info)
at Lai.Revit.ViewResults.ManageResults(View view, List`1 instances, PrimitiveMode mode)
at Lai.Revit.RevitTransactionWrapper.InvokeMethod[T](Object method)
at Lai.Revit.RevitTransactionWrapper.PerformTransaction[T](Document doc, Object method, String transactionName)
at Lai.Revit.RevitTransactionWrapper.InvokeTransactionWrapper[T](Document doc, Object method, TransactionWrapper wrapper, String transactionName, String errorMessage)
ElumTools 2018 Release 13 (2018.13.0.2)
Lai.Revit
2018.1.0.0
2018.1.0.0
C:\ProgramData\Autodesk\Revit\Addins\2018\!ElumTools.bundle\Lai.Revit.dll
Solution
Install .NET Framework Runtime 4.7.2 or later. The installer is available from Microsoft at this link.