Turn 'em on - lets see what is still a problem.

src/libraries/System.Private.Xml/tests/XmlSerializer/XmlSerializerTests.RuntimeOnly.cs

@@ -3196,7 +3196,6 @@ public static void XmlMembersMapping_Soap_MultipleMembers_IsReturnValue()
     }
 
     [Fact]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/1395")]
     public static void Xml_TypeWithReadOnlyMyCollectionProperty()
     {
         var value = new TypeWithReadOnlyMyCollectionProperty();
@@ -3366,7 +3365,6 @@ public static void Xml_NookTypes()
     }
 
     [Fact]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/60462", TestPlatforms.iOS | TestPlatforms.tvOS)]
     public static void DerivedTypeWithDifferentOverrides()
     {
         DerivedTypeWithDifferentOverrides value = new DerivedTypeWithDifferentOverrides() { Name1 = "Name1", Name2 = "Name2", Name3 = "Name3", Name4 = "Name4", Name5 = "Name5" };
@@ -3379,7 +3377,6 @@ public static void DerivedTypeWithDifferentOverrides()
     }
 
     [Fact]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/60462", TestPlatforms.iOS | TestPlatforms.tvOS)]
     public static void DerivedTypeWithDifferentOverrides2()
     {
         DerivedTypeWithDifferentOverrides2 value = new DerivedTypeWithDifferentOverrides2() { Name1 = "Name1", Name2 = "Name2", Name3 = "Name3", Name4 = "Name4", Name5 = "Name5", Name6 = "Name6", Name7 = "Name7" };

src/libraries/System.Private.Xml/tests/XmlSerializer/XmlSerializerTests.cs

@@ -265,7 +265,6 @@ public static void Xml_ListRoot()
     // horizon that it's not worth the trouble.
 #if !XMLSERIALIZERGENERATORTESTS
     [Fact]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/74247", TestPlatforms.tvOS)]
     public static void Xml_ReadOnlyCollection()
     {
         ReadOnlyCollection<string> roc = new ReadOnlyCollection<string>(new string[] { "one", "two" });
@@ -287,7 +286,6 @@ public static void Xml_ReadOnlyCollection()
 
     [Theory]
     [MemberData(nameof(Xml_ImmutableCollections_MemberData))]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/74247", TestPlatforms.tvOS)]
     public static void Xml_ImmutableCollections(Type type, object collection, Type createException, Type addException, string expectedXml, string exMsg = null)
     {
         XmlSerializer serializer;
@@ -2309,8 +2307,7 @@ public static void Xml_TypeWithSpecialCharacterInStringMember()
     // loaded in the default ALC, which causes problems for this test.
     [SkipOnPlatform(TestPlatforms.Browser, "AssemblyDependencyResolver not supported in wasm")]
 #endif
-    [ActiveIssue("34072", TestRuntimes.Mono)]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/96799", typeof(PlatformDetection), nameof(PlatformDetection.IsReadyToRunCompiled))]
+    [ActiveIssue("https://github.com/dotnet/runtime/issues/34072", TestRuntimes.Mono)]
     public static void Xml_TypeInCollectibleALC()
     {
         ExecuteAndUnload("SerializableAssembly.dll", "SerializationTypes.SimpleType", out var weakRef);

src/libraries/System.Runtime.Serialization.Schema/tests/System/Runtime/Serialization/Schema/RoundTripTest.cs

@@ -22,8 +22,10 @@ public RoundTripTest(ITestOutputHelper output)
         }
 
         [Fact]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsBrowser))]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsMonoRuntime), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsAppleMobile))]
+        // Passes on some wasm, but not all? Seems to have both passed and failed on the same browser/wasm/OS/Mono-CoreCLR combo in the same pipeline? How does that happen? Is this trimming related?
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming))]
+        //[ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsBrowser))]
+        //[ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsMonoRuntime), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsAppleMobile))]
         public void RountTripTest()
         {
             // AppContext SetSwitch seems to be unreliable in the unit test case. So let's not rely on it
@@ -81,7 +83,6 @@ public void RountTripTest()
         }
 
         [Fact]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsBrowser))]
         public void RoundTripXmlSerializableWithSpecialAttributesTest()
         {
             XsdDataContractExporter exporter = new XsdDataContractExporter();

src/libraries/System.Runtime.Serialization.Xml/tests/DataContractSerializerStressTests.cs

@@ -10,7 +10,6 @@
 public static partial class DataContractSerializerTests
 {
     [Fact]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/34962", TestRuntimes.Mono)]
     public static void DCS_MyPersonSurrogate_Stress()
     {
         // This test is to verify a bug fix made in ObjectToIdCache.cs.

src/libraries/System.Runtime.Serialization.Xml/tests/XmlDictionaryWriterTest.cs

@@ -495,7 +495,6 @@ void AssertBytesWritten(Action<XmlDictionaryWriter> action, XmlBinaryNodeType no
     }
 
     [Fact]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/85013", typeof(PlatformDetection), nameof(PlatformDetection.IsBrowser), nameof(PlatformDetection.IsMonoAOT))]
     public static void XmlBaseWriter_WriteString()
     {
         const byte Chars8Text = 152;

src/libraries/System.Runtime.Serialization.Xml/tests/XsdDataContractExporterTests/ExporterApiTests.cs

@@ -87,9 +87,10 @@ public static IEnumerable<object[]> CanExport_MemberData()
         }
 
         [Theory]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsBrowser))]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsWasi))]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsMonoRuntime), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsAppleMobile))]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming))]
+        //[ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsBrowser))]
+        //[ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsWasi))]
+        //[ActiveIssue("https://github.com/dotnet/runtime/issues/73961", typeof(PlatformDetection), nameof(PlatformDetection.IsMonoRuntime), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming), nameof(PlatformDetection.IsAppleMobile))]
         [MemberData(nameof(Export_MemberData))]
         public void Export(string testname, Action<XsdDataContractExporter> export, Action<string, XmlSchemaSet> schemaCheck = null)
         {

src/libraries/System.Runtime.Serialization.Xml/tests/XsdDataContractExporterTests/ExporterTypesTests.cs

@@ -80,8 +80,9 @@ public static IEnumerable<object[]> GetDynamicallyVersionedTypesTestNegativeData
         }
 
         [ConditionalTheory(typeof(PlatformDetection), nameof(PlatformDetection.DataSetXmlSerializationIsSupported))]
-        [SkipOnPlatform(TestPlatforms.Browser, "Inconsistent and unpredictable results.")]  // TODO - Why does 'TypeWithReadWriteCollectionAndNoCtorOnCollection' only cause an exception sometimes, but not all the time? What's special about wasm here?
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/82967", TestPlatforms.Wasi)]
+        //[SkipOnPlatform(TestPlatforms.Browser, "Inconsistent and unpredictable results.")]  // TODO - Why does 'TypeWithReadWriteCollectionAndNoCtorOnCollection' only cause an exception sometimes, but not all the time? What's special about wasm here?
+        //[ActiveIssue("https://github.com/dotnet/runtime/issues/82967", TestPlatforms.Wasi)]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/82967", typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltWithAggressiveTrimming))]
         [InlineData(typeof(NoDataContractWithoutParameterlessConstructor), typeof(InvalidDataContractException), @"Type 'System.Runtime.Serialization.Xml.XsdDataContractExporterTests.ExporterTypesTests+NoDataContractWithoutParameterlessConstructor' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. Alternatively, you can ensure that the type is public and has a parameterless constructor - all public members of the type will then be serialized, and no attributes will be required.")]
         [InlineData(typeof(DataContractWithInvalidMember), typeof(InvalidDataContractException), @"Type 'System.Runtime.Serialization.Xml.XsdDataContractExporterTests.ExporterTypesTests+NoDataContractWithoutParameterlessConstructor' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. Alternatively, you can ensure that the type is public and has a parameterless constructor - all public members of the type will then be serialized, and no attributes will be required.")]
         [InlineData(typeof(SerializableWithInvalidMember), typeof(InvalidDataContractException), @"Type 'System.Runtime.Serialization.Xml.XsdDataContractExporterTests.ExporterTypesTests+NoDataContractWithoutParameterlessConstructor' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. Alternatively, you can ensure that the type is public and has a parameterless constructor - all public members of the type will then be serialized, and no attributes will be required.")]