Index: Ringtoets/Common/src/Ringtoets.Common.IO/FileImporters/ProfilesImporter.cs
===================================================================
diff -u -rb3b6c13cf736c134476b3db34281332d01ca86b1 -r7fcfd2a51296e34e31b995e741e16da362ed745c
--- Ringtoets/Common/src/Ringtoets.Common.IO/FileImporters/ProfilesImporter.cs	(.../ProfilesImporter.cs)	(revision b3b6c13cf736c134476b3db34281332d01ca86b1)
+++ Ringtoets/Common/src/Ringtoets.Common.IO/FileImporters/ProfilesImporter.cs	(.../ProfilesImporter.cs)	(revision 7fcfd2a51296e34e31b995e741e16da362ed745c)
@@ -222,7 +222,8 @@
             }
             if (profileLocations.Any(dpl => dpl.Id.Equals(profileLocation.Id)))
             {
-                Log.WarnFormat(Resources.ProfilesImporter_AddNextProfileLocation_Location_with_id_0_already_read, profileLocation.Id);
+                string message = string.Format(Resources.ProfilesImporter_AddNextProfileLocation_Location_with_id_0_already_read, profileLocation.Id);
+                throw new CriticalFileReadException(message);
             }
             profileLocations.Add(profileLocation);
         }
@@ -268,38 +269,33 @@
 
                     if (dikeProfileData.Any(d => d.Id.Equals(data.Id)))
                     {
-                        LogDuplicate(data, prflFilePath);
+                        string errorMessage = string.Format(
+                            Resources.ProfilesImporter_LogDuplicateDikeProfileData_Multiple_DikeProfileData_found_for_DikeProfile_0_File_1_skipped,
+                            data.Id,
+                            prflFilePath);
+                        throw new CriticalFileReadException(errorMessage);
                     }
-                    else
-                    {
-                        dikeProfileData.Add(data);
-                    }
+
+                    dikeProfileData.Add(data);
                 }
                 // No need to catch ArgumentException, as prflFilePaths are valid by construction.
                 catch (CriticalFileReadException exception)
                 {
                     Log.Error(exception.Message);
-                    errorOccured = true;
+                    return new ReadResult<DikeProfileData>(true);
                 }
                 catch (CriticalFileValidationException)
                 {
                     // Ignore file
                 }
             }
 
-            return errorOccured && !dikeProfileData.Any()
-                       ? new ReadResult<DikeProfileData>(true)
-                       : new ReadResult<DikeProfileData>(false)
-                       {
-                           Items = dikeProfileData
-                       };
+            return new ReadResult<DikeProfileData>(false)
+            {
+                Items = dikeProfileData
+            };
         }
 
-        private void LogDuplicate(DikeProfileData data, string prflFilePath)
-        {
-            Log.WarnFormat(Resources.ProfilesImporter_LogDuplicateDikeProfileData_Multiple_DikeProfileData_found_for_DikeProfile_0_File_1_skipped, data.Id, prflFilePath);
-        }
-
         private double GetDistanceToReferenceLine(Point2D point)
         {
             return GetLineSegments(referenceLine.Points).Min(segment => segment.GetEuclideanDistanceToPoint(point));
Index: Ringtoets/Common/test/Ringtoets.Common.IO.Test/FileImporters/ProfilesImporterTest.cs
===================================================================
diff -u -rb3b6c13cf736c134476b3db34281332d01ca86b1 -r7fcfd2a51296e34e31b995e741e16da362ed745c
--- Ringtoets/Common/test/Ringtoets.Common.IO.Test/FileImporters/ProfilesImporterTest.cs	(.../ProfilesImporterTest.cs)	(revision b3b6c13cf736c134476b3db34281332d01ca86b1)
+++ Ringtoets/Common/test/Ringtoets.Common.IO.Test/FileImporters/ProfilesImporterTest.cs	(.../ProfilesImporterTest.cs)	(revision 7fcfd2a51296e34e31b995e741e16da362ed745c)
@@ -424,8 +424,9 @@
             var messageProvider = mocks.Stub<IImporterMessageProvider>();
             mocks.ReplayAll();
 
-            string filePath = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Integration.Plugin,
-                                                         Path.Combine("DikeProfiles", "InvalidDamType", "Voorlanden 12-2.shp"));
+            string testFileDirectory = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Integration.Plugin,
+                                                         Path.Combine("DikeProfiles", "InvalidDamType"));
+            string filePath = Path.Combine(testFileDirectory, "Voorlanden 12-2.shp");
 
             ReferenceLine referenceLine = CreateMatchingReferenceLine();
             var testProfilesImporter = new TestProfilesImporter(new ObservableList<TestProfile>(), referenceLine, filePath, messageProvider);
@@ -435,13 +436,10 @@
             Action call = () => importResult = testProfilesImporter.Import();
 
             // Assert
-            Action<IEnumerable<string>> asserts = messages =>
-            {
-                bool found = messages.Any(message => message.EndsWith(": het ingelezen damtype ('4') moet 0, 1, 2 of 3 zijn."));
-                Assert.IsTrue(found);
-            };
-            TestHelper.AssertLogMessages(call, asserts);
-            Assert.IsTrue(importResult);
+            string erroneousProfileFile = Path.Combine(testFileDirectory, "profiel005 - Ringtoets.prfl");
+            string expectedMessage = $"Fout bij het lezen van bestand '{erroneousProfileFile}' op regel 6: het ingelezen damtype ('4') moet 0, 1, 2 of 3 zijn.";
+            TestHelper.AssertLogMessageWithLevelIsGenerated(call, Tuple.Create(expectedMessage, LogLevelConstant.Error), 1);
+            Assert.IsFalse(importResult);
         }
 
         [Test]
@@ -451,8 +449,9 @@
             var messageProvider = mocks.Stub<IImporterMessageProvider>();
             mocks.ReplayAll();
 
-            string filePath = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Integration.Plugin,
-                                                         Path.Combine("DikeProfiles", "TwoPrflWithSameId", "profiel001.shp"));
+            string testFileDirectory = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Integration.Plugin,
+                                                         Path.Combine("DikeProfiles", "TwoPrflWithSameId"));
+            string filePath = Path.Combine(testFileDirectory, "profiel001.shp");
 
             var referencePoints = new List<Point2D>
             {
@@ -468,19 +467,14 @@
             Action call = () => importResult = testProfilesImporter.Import();
 
             // Assert
-            Action<IEnumerable<string>> asserts = messages =>
-            {
-                const string start = "Meerdere definities gevonden voor profiel 'profiel001'. Bestand '";
-                const string end = "' wordt overgeslagen.";
-                bool found = messages.Any(m => m.StartsWith(start) && m.EndsWith(end));
-                Assert.IsTrue(found);
-            };
-            TestHelper.AssertLogMessages(call, asserts);
-            Assert.IsTrue(importResult);
+            string erroneousProfileFile = Path.Combine(testFileDirectory, "profiel001_2.prfl");
+            string expectedMessage = $"Meerdere definities gevonden voor profiel 'profiel001'. Bestand '{erroneousProfileFile}' wordt overgeslagen.";
+            TestHelper.AssertLogMessageWithLevelIsGenerated(call, Tuple.Create(expectedMessage, LogLevelConstant.Error), 1);
+            Assert.IsFalse(importResult);
         }
 
         [Test]
-        public void Import_FromFileWithDupplicateId_TrueAndLogWarnings()
+        public void Import_FromFileWithDuplicateId_FalseAndLogErrors()
         {
             // Setup
             var messageProvider = mocks.Stub<IImporterMessageProvider>();
@@ -497,18 +491,13 @@
             Action call = () => importResult = testProfilesImporter.Import();
 
             // Assert
-            TestHelper.AssertLogMessages(call, messages =>
-            {
-                string[] messageArray = messages.ToArray();
-                const string expectedMessage = "Profiellocatie met ID 'profiel001' is opnieuw ingelezen.";
-                Assert.AreEqual(expectedMessage, messageArray[0]);
-                Assert.AreEqual(expectedMessage, messageArray[1]);
-            });
-            Assert.IsTrue(importResult);
+            const string expectedMessage = "Profiellocatie met ID 'profiel001' is opnieuw ingelezen.";
+            TestHelper.AssertLogMessageWithLevelIsGenerated(call, Tuple.Create(expectedMessage, LogLevelConstant.Error), 1);
+            Assert.IsFalse(importResult);
         }
 
         [Test]
-        public void Import_PrflWithProfileNotZero_TrueAndErrorLog()
+        public void Import_PrflWithProfileNotZero_FalseAndErrorLog()
         {
             // Setup
             var messageProvider = mocks.Stub<IImporterMessageProvider>();