diff --git a/src/TestFramework/TestFramework/Attributes/TestMethod/STATestMethodAttribute.cs b/src/TestFramework/TestFramework/Attributes/TestMethod/STATestMethodAttribute.cs
index dd423b5248..0d83f0230f 100644
--- a/src/TestFramework/TestFramework/Attributes/TestMethod/STATestMethodAttribute.cs
+++ b/src/TestFramework/TestFramework/Attributes/TestMethod/STATestMethodAttribute.cs
@@ -76,8 +76,7 @@ public override async Task<TestResult[]> ExecuteAsync(ITestMethod testMethod)
 #if !NETFRAMEWORK
         if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
         {
-            // TODO: Throw?
-            return await ExecuteCoreAsync(testMethod).ConfigureAwait(false);
+            throw new PlatformNotSupportedException(FrameworkMessages.STATestMethodNonWindowsNotSupported);
         }
 #endif
 
diff --git a/src/TestFramework/TestFramework/Resources/FrameworkMessages.resx b/src/TestFramework/TestFramework/Resources/FrameworkMessages.resx
index ee8056bb41..90350e2434 100644
--- a/src/TestFramework/TestFramework/Resources/FrameworkMessages.resx
+++ b/src/TestFramework/TestFramework/Resources/FrameworkMessages.resx
@@ -405,4 +405,7 @@ Actual: {2}</value>
   <data name="AssertScopeNestedNotAllowed" xml:space="preserve">
     <value>Nested assert scopes are not allowed. Dispose the current scope before creating a new one.</value>
   </data>
+  <data name="STATestMethodNonWindowsNotSupported" xml:space="preserve">
+    <value>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</value>
+  </data>
 </root>
\ No newline at end of file
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.cs.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.cs.xlf
index 4ba65efbe5..92af94f70f 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.cs.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.cs.xlf
@@ -358,6 +358,11 @@ Skutečnost: {2}</target>
         <target state="translated">Elementy &lt;{0}&gt; se v kolekci nenachází.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">Řetězec „{0}“ nezačíná řetězcem „{1}“. {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.de.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.de.xlf
index 68c705ab3c..361def958a 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.de.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.de.xlf
@@ -358,6 +358,11 @@ Tatsächlich: {2}</target>
         <target state="translated">Element(e) &lt;{0}&gt; ist/sind in der Auflistung nicht vorhanden.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">Die Zeichenfolge „{0}“ beginnt nicht mit der Zeichenfolge „{1}“. {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.es.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.es.xlf
index 09f2d652ff..9b86c3bb13 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.es.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.es.xlf
@@ -358,6 +358,11 @@ Real: {2}</target>
         <target state="translated">Los elementos &lt;{0}&gt; no están presentes en la colección.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">La cadena "{0}" no empieza con la cadena "{1}". {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.fr.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.fr.xlf
index 141e1fb731..fcd01ce0ee 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.fr.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.fr.xlf
@@ -358,6 +358,11 @@ Réel : {2}</target>
         <target state="translated">L’élément ou les éléments &lt;{0}&gt; n’est ou ne sont pas présent(s) dans la collection.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">La chaîne '{0}' ne commence pas par la chaîne '{1}'. {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.it.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.it.xlf
index e2b3fada9c..0ae3b6e713 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.it.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.it.xlf
@@ -358,6 +358,11 @@ Effettivo: {2}</target>
         <target state="translated">Gli elementi &lt;{0}&gt; non sono presenti nella raccolta.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">La stringa '{0}' non inizia con la stringa '{1}'. {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ja.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ja.xlf
index 7edf1c0606..347c2f890e 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ja.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ja.xlf
@@ -358,6 +358,11 @@ Actual: {2}</source>
         <target state="translated">要素 &lt;{0}&gt; がコレクション内に存在しません。</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">文字列 '{0}' は文字列 '{1}' で始まりません。{2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ko.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ko.xlf
index a6707c4ce1..1327c841d3 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ko.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ko.xlf
@@ -358,6 +358,11 @@ Actual: {2}</source>
         <target state="translated">컬렉션에 &lt;{0}&gt; 요소가 없습니다.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">'{0}' 문자열이 '{1}' 문자열로 시작되지 않습니다. {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pl.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pl.xlf
index 1174de42f7..b275678564 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pl.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pl.xlf
@@ -358,6 +358,11 @@ Rzeczywiste: {2}</target>
         <target state="translated">Elementy &lt;{0}&gt; nie występują w kolekcji.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">Ciąg „{0}” nie rozpoczyna się od ciągu „{1}”. {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pt-BR.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pt-BR.xlf
index 2e6788a2d2..b71a8b0911 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pt-BR.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pt-BR.xlf
@@ -358,6 +358,11 @@ Real: {2}</target>
         <target state="translated">O(s) elemento(s) &lt;{0}&gt; não está/estão presente(s) na coleção.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">A cadeia de caracteres “{0}” não começa com a cadeia de caracteres “{1}”. {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ru.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ru.xlf
index 37f23e6a2a..614b3c3acf 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ru.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ru.xlf
@@ -358,6 +358,11 @@ Actual: {2}</source>
         <target state="translated">Элементы &lt;{0}&gt; отсутствуют в коллекции.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">Строка "{0}" не начинается со строки "{1}". {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.tr.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.tr.xlf
index 21c3eca9bc..f022bd7c10 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.tr.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.tr.xlf
@@ -358,6 +358,11 @@ Gerçekte olan: {2}</target>
         <target state="translated">Öğe(ler) &lt;{0}&gt; koleksiyonda mevcut değildir.</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">'{0}' dizesi, '{1}' dizesi ile başlamıyor. {2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hans.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hans.xlf
index 8d2e003c00..d55eae7400 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hans.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hans.xlf
@@ -358,6 +358,11 @@ Actual: {2}</source>
         <target state="translated">集合中不存在元素 &lt;{0}&gt;。</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">字符串 '{0}' 不以字符串 '{1}' 开头。{2}</target>
diff --git a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hant.xlf b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hant.xlf
index 9917c4d793..f306bbd038 100644
--- a/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hant.xlf
+++ b/src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hant.xlf
@@ -358,6 +358,11 @@ Actual: {2}</source>
         <target state="translated">集合中不存在元素 &lt;{0}&gt;。</target>
         <note />
       </trans-unit>
+      <trans-unit id="STATestMethodNonWindowsNotSupported">
+        <source>[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</source>
+        <target state="new">[STATestMethod] is not supported on non-Windows platforms. STA (Single Threaded Apartment) is a Windows-only COM threading concept. Use [OSCondition(OperatingSystems.Windows)] to skip this test on non-Windows platforms.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="StartsWithFail">
         <source>String '{0}' does not start with string '{1}'. {2}</source>
         <target state="translated">字串 '{0}' 不是以字串 '{1}' 開頭。{2}</target>