Index: Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Service/GrassCoverErosionInwardsCalculationService.cs
===================================================================
diff -u -r30b8231f92b90ea4b05e98e3d0285368f6dfe2e4 -r5cdaf6a62202805aa0abe5636e372a66b1bec723
--- Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Service/GrassCoverErosionInwardsCalculationService.cs	(.../GrassCoverErosionInwardsCalculationService.cs)	(revision 30b8231f92b90ea4b05e98e3d0285368f6dfe2e4)
+++ Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Service/GrassCoverErosionInwardsCalculationService.cs	(.../GrassCoverErosionInwardsCalculationService.cs)	(revision 5cdaf6a62202805aa0abe5636e372a66b1bec723)
@@ -77,7 +77,7 @@
             var exceedanceProbabilityCalculationParser = new ExceedanceProbabilityCalculationParser();
             var waveHeightParser = new OvertoppingCalculationWaveHeightParser();
 
-            HydraRingCalculationService.PerformCalculation(
+            HydraRingCalculationService.Instance.PerformCalculation(
                 hlcdDirectory,
                 ringId,
                 HydraRingUncertaintiesType.All,
@@ -120,7 +120,7 @@
 
             DikeHeightCalculationInput dikeHeightCalculationInput = CreateDikeHeightInput(calculation, assessmentSection, failureMechanismSection, generalInput);
 
-            HydraRingCalculationService.PerformCalculation(
+            HydraRingCalculationService.Instance.PerformCalculation(
                 hlcdDirectory,
                 ringId,
                 HydraRingUncertaintiesType.All,