diff --git a/build.cake b/build.cake
index 82a49adc..2227f832 100644
--- a/build.cake
+++ b/build.cake
@@ -12,8 +12,8 @@ var configuration = Argument("configuration", "Release");
 // SET PACKAGE VERSION
 //////////////////////////////////////////////////////////////////////
 
-var version = "4.2.0";
-var modifier = "";
+var version = "4.2.1";
+var modifier = "-dev.2";
 
 var dbgSuffix = configuration.ToLower() == "debug" ? "-dbg" : "";
 var packageVersion = version + modifier + dbgSuffix;
diff --git a/src/NUnit.TestAdapter.Tests.Acceptance/FilterTests.cs b/src/NUnit.TestAdapter.Tests.Acceptance/FilterTests.cs
index e339c409..7a4a1c81 100644
--- a/src/NUnit.TestAdapter.Tests.Acceptance/FilterTests.cs
+++ b/src/NUnit.TestAdapter.Tests.Acceptance/FilterTests.cs
@@ -15,19 +15,19 @@ namespace Filter
                     public class Tests
                     {
         
-                        [Test,Category(""FooGroup"")]
+                        [Test,Category(""FooGroup""),Category(""AllGroup"")]
                         public void Foo()
                         {
                             Assert.Pass();
                         }
 
-                        [Test,Explicit,Category(""IsExplicit""),Category(""FooGroup"")]
+                        [Test,Explicit,Category(""IsExplicit""),Category(""FooGroup""),Category(""AllGroup"")]
                         public void FooExplicit()
                         {
                             Assert.Pass();
                         }
 
-                        [Test, Category(""BarGroup"")]
+                        [Test, Category(""BarGroup""),Category(""AllGroup"")]
                         public void Bar()
                         {
                             Assert.Pass();
@@ -45,6 +45,8 @@ public void Bar()
         [TestCase(@"TestCategory=IsExplicit", 1, 1)]
         [TestCase(@"FullyQualifiedName=Filter.Tests.Foo", 1, 1)]
         [TestCase(@"FullyQualifiedName!=Filter.Tests.Foo", 1, 1)]
+        [TestCase(@"TestCategory!=AllGroup", 0, 0)]
+        // [TestCase(@"TestThatDontExistHere", 0, 0)]
         // [TestCase(@"FullyQualifiedName~Filter.Tests.Foo", 1, 1)]
         // [TestCase(@"FullyQualifiedName~Foo", 1, 1)]
         public void Filter_DotNetTest(string filter, int executed, int total)
diff --git a/src/NUnitTestAdapter/Execution.cs b/src/NUnitTestAdapter/Execution.cs
index b38f4bb6..74c605cf 100644
--- a/src/NUnitTestAdapter/Execution.cs
+++ b/src/NUnitTestAdapter/Execution.cs
@@ -74,6 +74,8 @@ protected TestFilter CheckFilter(TestFilter testFilter, IDiscoveryConverter disc
                 var filter = TestFilter.Empty;
                 return filter;
             }
+            if (discovery.NoOfLoadedTestCases == 0)
+                return testFilter;
             if (testFilter.IsCategoryFilter())
             {
                 if (!discovery.IsExplicitRun && discovery.HasExplicitTests && Settings.ExplicitMode == ExplicitModeEnum.Strict)