diff --git a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/EngineConfiguration.cs b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/EngineConfiguration.cs
index fc207b0c..8cb35308 100644
--- a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/EngineConfiguration.cs
+++ b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/EngineConfiguration.cs
@@ -29,7 +29,8 @@ public class EngineConfiguration : Engine
 
         public override string GetEngineExecutableName()
         {
-#if UNITY_STANDALONE_WIN
+            //Host-OS gate: a Windows Editor must still look for the .exe whatever the build target.
+#if UNITY_STANDALONE_WIN || UNITY_EDITOR_WIN
             return engineAppName + ".exe";
 #else 
             return engineAppName;
diff --git a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/EngineProcess.cs b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/EngineProcess.cs
index e2f0cbe6..07c6774c 100644
--- a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/EngineProcess.cs
+++ b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/EngineProcess.cs
@@ -29,11 +29,14 @@ internal sealed class EngineProcess : IDisposable
         /// <param name="logger"></param>
         public EngineProcess(Engine engine, IWebBrowserLogger logger)
         {
-#if UNITY_STANDALONE_WIN
+            //Host-OS gate, matching WebBrowserUtils.GetRunningPlatform(). Without the editor
+            //defines processHandle stayed null in an Editor targeting a non-Standalone platform
+            //and every member that forwards to it threw a NullReferenceException.
+#if UNITY_STANDALONE_WIN || UNITY_EDITOR_WIN
             processHandle = new WindowProcess();
-#elif UNITY_STANDALONE_LINUX
+#elif UNITY_STANDALONE_LINUX || UNITY_EDITOR_LINUX
             processHandle = new LinuxProcess(logger);
-#elif UNITY_STANDALONE_OSX
+#elif UNITY_STANDALONE_OSX || UNITY_EDITOR_OSX
             processHandle = new MacOsProcess();
 #endif
             
diff --git a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/LinuxProcess.cs b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/LinuxProcess.cs
index 702de1f4..4bf43086 100644
--- a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/LinuxProcess.cs
+++ b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/LinuxProcess.cs
@@ -3,7 +3,8 @@
 // 
 // This project is under the MIT license. See the LICENSE.md file for more details.
 
-#if UNITY_STANDALONE_LINUX
+//Host-OS gate (parity with WindowProcess).
+#if UNITY_STANDALONE_LINUX || UNITY_EDITOR_LINUX
 
 using System;
 using System.Collections.Generic;
diff --git a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/MacOsProcess.cs b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/MacOsProcess.cs
index 18e1297d..8c6acd54 100644
--- a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/MacOsProcess.cs
+++ b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/MacOsProcess.cs
@@ -6,7 +6,8 @@
 using System.Diagnostics;
 using VoltstroStudios.UnityWebBrowser.Helper;
 
-#if UNITY_STANDALONE_OSX
+//Host-OS gate (parity with WindowProcess).
+#if UNITY_STANDALONE_OSX || UNITY_EDITOR_OSX
 
 namespace VoltstroStudios.UnityWebBrowser.Core.Engines.Process
 {
diff --git a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/WindowProcess.cs b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/WindowProcess.cs
index 71128203..fb81c335 100644
--- a/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/WindowProcess.cs
+++ b/src/Packages/UnityWebBrowser/Runtime/Core/Engines/Process/WindowProcess.cs
@@ -3,7 +3,9 @@
 // 
 // This project is under the MIT license. See the LICENSE.md file for more details.
 
-#if UNITY_STANDALONE_WIN
+//Host-OS gate: this process wrapper has to compile for a Windows Editor whatever the
+//active build target is, because the engine is a child process of the Editor itself.
+#if UNITY_STANDALONE_WIN || UNITY_EDITOR_WIN
 
 using System;
 using System.ComponentModel;
diff --git a/src/Packages/UnityWebBrowser/Runtime/Helper/WebBrowserUtils.cs b/src/Packages/UnityWebBrowser/Runtime/Helper/WebBrowserUtils.cs
index 3f8d088a..aabdc1b6 100644
--- a/src/Packages/UnityWebBrowser/Runtime/Helper/WebBrowserUtils.cs
+++ b/src/Packages/UnityWebBrowser/Runtime/Helper/WebBrowserUtils.cs
@@ -140,11 +140,17 @@ public static bool GetScreenPointToLocalPositionDeltaOnImage(Graphic graphic, Ve
         /// <returns></returns>
         public static Platform GetRunningPlatform()
         {
-#if UNITY_STANDALONE_WIN
+            //Gated on the HOST OS, not the active build target. The engine is a native child
+            //process of the running Unity process, so in the Editor the platform that matters is
+            //the one the Editor itself runs on - a Windows Editor targeting WebGL/Android/console
+            //still has to launch the Windows engine. Keying this off UNITY_STANDALONE_* alone made
+            //this throw in any Editor whose build target was not Standalone, which stopped UWB
+            //being usable in the Editor for those projects at all.
+#if UNITY_STANDALONE_WIN || UNITY_EDITOR_WIN
             return Platform.Windows64;
-#elif UNITY_STANDALONE_LINUX
+#elif UNITY_STANDALONE_LINUX || UNITY_EDITOR_LINUX
             return Platform.Linux64;
-#elif UNITY_STANDALONE_OSX
+#elif UNITY_STANDALONE_OSX || UNITY_EDITOR_OSX
             return System.Runtime.InteropServices.RuntimeInformation.ProcessArchitecture == System.Runtime.InteropServices.Architecture.Arm64 ? Platform.MacOSArm64 : Platform.MacOS;
 #else
             throw new PlatformNotSupportedException();