Index: Ringtoets/Common/src/Ringtoets.Common.Service/Properties/Resources.Designer.cs
===================================================================
diff -u -rd4d68b519b90ce17bcfa75b0acc970c45a12fecf -r6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb
--- Ringtoets/Common/src/Ringtoets.Common.Service/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision d4d68b519b90ce17bcfa75b0acc970c45a12fecf)
+++ Ringtoets/Common/src/Ringtoets.Common.Service/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb)
@@ -40,7 +40,7 @@
     // class via a tool like ResGen or Visual Studio.
     // To add or remove a member, edit your .ResX file then rerun ResGen
     // with the /str option, or rebuild your VS project.
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "4.0.0.0")]
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "15.0.0.0")]
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
     public class Resources {
@@ -331,6 +331,16 @@
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to Doelkans is te klein om een berekening uit te kunnen voeren..
+        /// </summary>
+        public static string TargetProbabilityCalculationServiceHelper_ValidateTargetProbability_Target_probability_too_small {
+            get {
+                return ResourceManager.GetString("TargetProbabilityCalculationServiceHelper_ValidateTargetProbability_Target_probab" +
+                        "ility_too_small", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to Validatie is beëindigd..
         /// </summary>
         public static string Validation_ended {
Index: Ringtoets/Common/src/Ringtoets.Common.Service/Properties/Resources.resx
===================================================================
diff -u -rd4d68b519b90ce17bcfa75b0acc970c45a12fecf -r6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb
--- Ringtoets/Common/src/Ringtoets.Common.Service/Properties/Resources.resx	(.../Resources.resx)	(revision d4d68b519b90ce17bcfa75b0acc970c45a12fecf)
+++ Ringtoets/Common/src/Ringtoets.Common.Service/Properties/Resources.resx	(.../Resources.resx)	(revision 6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb)
@@ -221,4 +221,7 @@
   <data name="TargetProbabilityCalculationServiceHelper_ValidateTargetProbability_Target_probability_too_big" xml:space="preserve">
     <value>Doelkans is te groot om een berekening uit te kunnen voeren.</value>
   </data>
+  <data name="TargetProbabilityCalculationServiceHelper_ValidateTargetProbability_Target_probability_too_small" xml:space="preserve">
+    <value>Doelkans is te klein om een berekening uit te kunnen voeren.</value>
+  </data>
 </root>
\ No newline at end of file
Index: Ringtoets/Common/src/Ringtoets.Common.Service/TargetProbabilityCalculationServiceHelper.cs
===================================================================
diff -u -r8d14456703e8c6cc42cc5474817c92f9141eb72b -r6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb
--- Ringtoets/Common/src/Ringtoets.Common.Service/TargetProbabilityCalculationServiceHelper.cs	(.../TargetProbabilityCalculationServiceHelper.cs)	(revision 8d14456703e8c6cc42cc5474817c92f9141eb72b)
+++ Ringtoets/Common/src/Ringtoets.Common.Service/TargetProbabilityCalculationServiceHelper.cs	(.../TargetProbabilityCalculationServiceHelper.cs)	(revision 6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb)
@@ -55,7 +55,12 @@
             if (targetBeta < -1)
             {
                 handleLogMessageAction(Resources.TargetProbabilityCalculationServiceHelper_ValidateTargetProbability_Target_probability_too_big);
+                return false;
+            }
 
+            if (targetBeta > 40)
+            {
+                handleLogMessageAction(Resources.TargetProbabilityCalculationServiceHelper_ValidateTargetProbability_Target_probability_too_small);
                 return false;
             }
 
Index: Ringtoets/Common/test/Ringtoets.Common.Service.Test/TargetProbabilityCalculationServiceHelperTest.cs
===================================================================
diff -u -r8d14456703e8c6cc42cc5474817c92f9141eb72b -r6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb
--- Ringtoets/Common/test/Ringtoets.Common.Service.Test/TargetProbabilityCalculationServiceHelperTest.cs	(.../TargetProbabilityCalculationServiceHelperTest.cs)	(revision 8d14456703e8c6cc42cc5474817c92f9141eb72b)
+++ Ringtoets/Common/test/Ringtoets.Common.Service.Test/TargetProbabilityCalculationServiceHelperTest.cs	(.../TargetProbabilityCalculationServiceHelperTest.cs)	(revision 6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb)
@@ -84,6 +84,21 @@
             Assert.AreEqual("Doelkans is te groot om een berekening uit te kunnen voeren.", logMessage);
         }
 
+        [Test]
+        [TestCaseSource(nameof(TargetProbabilitiesThatAreTooSmall))]
+        public void ValidateTargetProbability_TargetProbabilityTooSmall_ReturnsFalseAndHandlesExpectedLogMessage(double targetProbability)
+        {
+            // Setup
+            string logMessage = string.Empty;
+
+            // Call
+            bool isValid = TargetProbabilityCalculationServiceHelper.ValidateTargetProbability(targetProbability, lm => logMessage = lm);
+
+            // Assert
+            Assert.IsFalse(isValid);
+            Assert.AreEqual("Doelkans is te klein om een berekening uit te kunnen voeren.", logMessage);
+        }
+
         private static IEnumerable<TestCaseData> ValidTargetProbabilities()
         {
             yield return new TestCaseData(0.005);
@@ -95,5 +110,11 @@
             yield return new TestCaseData(StatisticsConverter.ReliabilityToProbability(-1.005));
             yield return new TestCaseData(5.0);
         }
+
+        private static IEnumerable<TestCaseData> TargetProbabilitiesThatAreTooSmall()
+        {
+            yield return new TestCaseData(StatisticsConverter.ReliabilityToProbability(40.005));
+            yield return new TestCaseData(0.0);
+        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Common/test/Ringtoets.Common.Service.Test/TargetProbabilityCalculationServiceTest.cs
===================================================================
diff -u -r08a74809d225be7c226def1b19d3e3bc9a6fb677 -r6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb
--- Ringtoets/Common/test/Ringtoets.Common.Service.Test/TargetProbabilityCalculationServiceTest.cs	(.../TargetProbabilityCalculationServiceTest.cs)	(revision 08a74809d225be7c226def1b19d3e3bc9a6fb677)
+++ Ringtoets/Common/test/Ringtoets.Common.Service.Test/TargetProbabilityCalculationServiceTest.cs	(.../TargetProbabilityCalculationServiceTest.cs)	(revision 6d8bf9569d5fbf8b2591b00f5beca9a2fd9572cb)
@@ -177,6 +177,29 @@
             Assert.IsFalse(valid);
         }
 
+        [Test]
+        public void Validate_TargetProbabilityInvalidTooSmall_LogsErrorAndReturnsFalse()
+        {
+            // Setup
+            var valid = true;
+
+            // Call
+            Action call = () => valid = calculationService.Validate(validFilePath,
+                                                                    validPreprocessorDirectory,
+                                                                    0.0);
+
+            // Assert
+            TestHelper.AssertLogMessages(call, messages =>
+            {
+                string[] msgs = messages.ToArray();
+                Assert.AreEqual(3, msgs.Length);
+                CalculationServiceTestHelper.AssertValidationStartMessage(msgs[0]);
+                Assert.AreEqual("Doelkans is te klein om een berekening uit te kunnen voeren.", msgs[1]);
+                CalculationServiceTestHelper.AssertValidationEndMessage(msgs[2]);
+            });
+            Assert.IsFalse(valid);
+        }
+
         private class TestTargetProbabilityCalculationService : TargetProbabilityCalculationService {}
     }
 }
\ No newline at end of file