diff --git a/Documentation/docs-mobile/messages/index.md b/Documentation/docs-mobile/messages/index.md
index 95da6f0074e..d072096d78b 100644
--- a/Documentation/docs-mobile/messages/index.md
+++ b/Documentation/docs-mobile/messages/index.md
@@ -246,6 +246,7 @@ Either change the value in the AndroidManifest.xml to match the $(SupportedOSPla
 + [XA5300](xa5300.md): The Android/Java SDK Directory could not be found.
 + [XA5301](xa5301.md): Failed to generate Java type for class: {managedType} due to MAX_PATH: {exception}
 + [XA5302](xa5302.md): Two processes may be building this project at once. Lock file exists at path: {path}
++ [XA5303](xa5303.md): Failed to parse 'DescriptorIndex' metadata value '{value}' for assembly '{assembly}'.
 
 ## XA6xxx: Internal tools
 
diff --git a/Documentation/docs-mobile/messages/xa5303.md b/Documentation/docs-mobile/messages/xa5303.md
new file mode 100644
index 00000000000..3fe9996bf78
--- /dev/null
+++ b/Documentation/docs-mobile/messages/xa5303.md
@@ -0,0 +1,23 @@
+---
+title: .NET for Android error XA5303
+description: XA5303 error code
+ms.date: 05/20/2026
+f1_keywords:
+  - "XA5303"
+---
+
+# .NET for Android error XA5303
+
+## Example messages
+
+```
+error XA5303: Failed to parse 'DescriptorIndex' metadata value 'abc' for assembly 'MyAssembly.dll'.
+```
+
+## Issue
+
+The `DescriptorIndex` metadata on an assembly item passed to the `CompressAssemblies` MSBuild task could not be parsed as an unsigned integer. This metadata is required for LZ4 assembly compression.
+
+## Solution
+
+This is typically an internal build system error. If you encounter this error, please file a [bug report](https://github.com/dotnet/android/issues/new).
diff --git a/src/Xamarin.Android.Build.Tasks/Properties/Resources.Designer.cs b/src/Xamarin.Android.Build.Tasks/Properties/Resources.Designer.cs
index f91bf212cd5..0b939e58fc0 100644
--- a/src/Xamarin.Android.Build.Tasks/Properties/Resources.Designer.cs
+++ b/src/Xamarin.Android.Build.Tasks/Properties/Resources.Designer.cs
@@ -1856,6 +1856,15 @@ public static string XA5302 {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Failed to parse &apos;DescriptorIndex&apos; metadata value &apos;{0}&apos; for assembly &apos;{1}&apos;..
+        /// </summary>
+        public static string XA5303 {
+            get {
+                return ResourceManager.GetString("XA5303", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Could not find Android Resource &apos;{0}&apos;. Please update @(AndroidResource) to add the missing resource..
         /// </summary>
diff --git a/src/Xamarin.Android.Build.Tasks/Properties/Resources.resx b/src/Xamarin.Android.Build.Tasks/Properties/Resources.resx
index 176461e6d71..e872cdea50c 100644
--- a/src/Xamarin.Android.Build.Tasks/Properties/Resources.resx
+++ b/src/Xamarin.Android.Build.Tasks/Properties/Resources.resx
@@ -924,6 +924,12 @@ To use a custom JDK path for a command line build, set the 'JavaSdkDirectory' MS
   <data name="XA5302" xml:space="preserve">
     <value>Two processes may be building this project at once. Lock file exists at path: {0}</value>
   </data>
+  <data name="XA5303" xml:space="preserve">
+    <value>Failed to parse 'DescriptorIndex' metadata value '{0}' for assembly '{1}'.</value>
+    <comment>
+{0} - The DescriptorIndex metadata value that could not be parsed
+{1} - The assembly ItemSpec</comment>
+  </data>
   <data name="XA_Manifest_AutoGenerated_Header" xml:space="preserve">
     <value>
     This code was generated by a tool.
diff --git a/src/Xamarin.Android.Build.Tasks/Tasks/CompressAssemblies.cs b/src/Xamarin.Android.Build.Tasks/Tasks/CompressAssemblies.cs
index f2730a732d2..039cfc0626c 100644
--- a/src/Xamarin.Android.Build.Tasks/Tasks/CompressAssemblies.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tasks/CompressAssemblies.cs
@@ -35,7 +35,7 @@ public override bool RunTask ()
 				break;
 
 			if (!uint.TryParse (descriptor_index_string, out var descriptor_index)) {
-				Log.LogError ($"Failed to parse 'DescriptorIndex' metadata value '{descriptor_index_string}' for assembly '{assembly.ItemSpec}'");
+				Log.LogCodedError ("XA5303", Properties.Resources.XA5303, descriptor_index_string, assembly.ItemSpec);
 				break;
 			}