diff --git a/src/ZB.MOM.WW.ScadaBridge.InboundAPI/InboundScriptExecutor.cs b/src/ZB.MOM.WW.ScadaBridge.InboundAPI/InboundScriptExecutor.cs
index bcfb0714..782db41a 100644
--- a/src/ZB.MOM.WW.ScadaBridge.InboundAPI/InboundScriptExecutor.cs
+++ b/src/ZB.MOM.WW.ScadaBridge.InboundAPI/InboundScriptExecutor.cs
@@ -110,14 +110,26 @@ public class InboundScriptExecutor
     }
 
     /// <summary>
-    /// Removes a compiled script handler for a method name.
+    /// Drops the compiled handler AND any known-bad record for the method. The
+    /// consumption seam for the script-artifact invalidation contract (bundle import,
+    /// out-of-band updates, failover activation). Safe to call for unknown names.
+    /// The per-request revision check in ExecuteAsync remains the correctness
+    /// fallback when an invalidation is missed.
     /// </summary>
-    /// <param name="methodName">The method name to remove.</param>
-    public void RemoveHandler(string methodName)
+    /// <param name="methodName">The method name to invalidate.</param>
+    public void InvalidateMethod(string methodName)
     {
         _scriptHandlers.TryRemove(methodName, out _);
+        _knownBadMethods.TryRemove(methodName, out _);
     }
 
+    /// <summary>
+    /// Removes a compiled script handler for a method name. Delegates to
+    /// <see cref="InvalidateMethod"/> (public API preserved).
+    /// </summary>
+    /// <param name="methodName">The method name to remove.</param>
+    public void RemoveHandler(string methodName) => InvalidateMethod(methodName);
+
     /// <summary>
     /// Compiles and registers a single API method script. Returns <c>false</c> if the
     /// script is empty, fails Roslyn compilation, or violates the script trust model.
diff --git a/src/ZB.MOM.WW.ScadaBridge.ManagementService/ManagementActor.cs b/src/ZB.MOM.WW.ScadaBridge.ManagementService/ManagementActor.cs
index c78184f8..29e2eda1 100644
--- a/src/ZB.MOM.WW.ScadaBridge.ManagementService/ManagementActor.cs
+++ b/src/ZB.MOM.WW.ScadaBridge.ManagementService/ManagementActor.cs
@@ -2651,7 +2651,7 @@ public class ManagementActor : ReceiveActor
         await repo.DeleteApiMethodAsync(cmd.ApiMethodId);
         await repo.SaveChangesAsync();
         if (method != null)
-            sp.GetService<InboundAPI.InboundScriptExecutor>()?.RemoveHandler(method.Name);
+            sp.GetService<InboundAPI.InboundScriptExecutor>()?.InvalidateMethod(method.Name);
         await AuditAsync(sp, user, "Delete", "ApiMethod", cmd.ApiMethodId.ToString(), method?.Name ?? cmd.ApiMethodId.ToString(), null);
         return true;
     }
diff --git a/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorStalenessTests.cs b/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorStalenessTests.cs
index 3f39c481..88f8e8d0 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorStalenessTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorStalenessTests.cs
@@ -86,4 +86,21 @@ public class InboundScriptExecutorStalenessTests
         Assert.True(r.Success);
         Assert.Contains("99", r.ResultJson);
     }
+
+    [Fact]
+    public async Task InvalidateMethod_DropsHandlerAndKnownBadRecord()
+    {
+        var good = new ApiMethod("inv", "return 5;") { Id = 5, TimeoutSeconds = 10 };
+        Assert.True(_executor.CompileAndRegister(good));
+        var broken = new ApiMethod("invbad", "%%%") { Id = 6, TimeoutSeconds = 10 };
+        Assert.False(_executor.CompileAndRegister(broken));
+
+        _executor.InvalidateMethod("inv");
+        _executor.InvalidateMethod("invbad");
+
+        Assert.Equal(0, _executor.KnownBadMethodCount);
+        // After invalidation the method lazily recompiles from the row — still serves.
+        var r = await Run(good);
+        Assert.True(r.Success);
+    }
 }