public sealed class TopologyError 

{
  static void ProcessTopologyErrors()
  {
    using (Geodatabase geodatabase = new Geodatabase(new FileGeodatabaseConnectionPath(new Uri(@"C:\TestData\GrandTeton.gdb"))))
    using (ArcGIS.Core.Data.Topology.Topology topology = geodatabase.OpenDataset<ArcGIS.Core.Data.Topology.Topology>("Backcountry_Topology"))
    {
      // Get all the errors and exceptions currently associated with the topology.
      IReadOnlyList<TopologyError> allErrorsAndExceptions = topology.GetErrors(new ErrorDescription(topology.GetExtent()));

      Console.WriteLine($"errors and exceptions count => {allErrorsAndExceptions.Count}");
      Console.WriteLine("OriginClassName \t OriginObjectID \t DestinationClassName \t DestinationObjectID \t RuleType \t IsException \t Shape type \t Shape width & height \t  Rule ID \t");

      foreach (TopologyError error in allErrorsAndExceptions)
      {
        Console.WriteLine(
          $"'{error.OriginClassName}' \t {error.OriginObjectID} \t '{error.DestinationClassName}' \t " +
          $"{error.DestinationObjectID} \t {error.RuleType} \t {error.IsException} \t {error.Shape.GeometryType} \t " +
          $"{error.Shape.Extent.Width},{error.Shape.Extent.Height} \t {error.RuleID}");
      }
    }
  }
}

{
  static void MarkAndUnmarkAsErrors(ArcGIS.Core.Data.Topology.Topology topology)
  {
    // Get all the errors due to features violating the "PointProperlyInsideArea" topology rule.
    using (TopologyDefinition topologyDefinition = topology.GetDefinition())
    {
      TopologyRule pointProperlyInsideAreaRule = topologyDefinition.GetRules().First(rule => rule.RuleType == TopologyRuleType.PointProperlyInsideArea);

      ErrorDescription errorDescription = new ErrorDescription(topology.GetExtent())
      {
        TopologyRule = pointProperlyInsideAreaRule
      };

      IReadOnlyList<TopologyError> errorsDueToViolatingPointProperlyInsideAreaRule = topology.GetErrors(errorDescription);
      Console.WriteLine($"There are {errorsDueToViolatingPointProperlyInsideAreaRule.Count} feature violating the 'PointProperlyInsideArea' topology rule.");

      // Mark all errors from features violating the 'PointProperlyInsideArea' topology rule as exceptions.
      foreach (TopologyError error in errorsDueToViolatingPointProperlyInsideAreaRule)
      {
        topology.MarkAsException(error);
      }

      // Now verify all the errors from features violating the 'PointProperlyInsideArea' topology rule have indeed been
      // marked as exceptions.
      //
      // By default, ErrorDescription is initialized to ErrorType.ErrorAndException.  Here we want ErrorType.ErrorOnly.
      errorDescription = new ErrorDescription(topology.GetExtent())
      {
        ErrorType = ErrorType.ErrorOnly,
        TopologyRule = pointProperlyInsideAreaRule
      };

      IReadOnlyList<TopologyError> errorsAfterMarkedAsExceptions = topology.GetErrors(errorDescription);
      Console.WriteLine($"There are {errorsAfterMarkedAsExceptions.Count} feature violating the 'PointProperlyInsideArea' topology rule after all the errors have been marked as exceptions.");

      // Finally, reset all the exceptions as errors by unmarking them as exceptions.

      foreach (TopologyError error in errorsDueToViolatingPointProperlyInsideAreaRule)
      {
        topology.UnmarkAsException(error);
      }

      IReadOnlyList<TopologyError> errorsAfterUnmarkedAsExceptions = topology.GetErrors(errorDescription);
      Console.WriteLine($"There are {errorsAfterUnmarkedAsExceptions.Count} feature violating the 'PointProperlyInsideArea' topology rule after all the exceptions have been reset as errors.");
    }
  }
}