diff --git a/.github/ARCHITECTURE.md b/.github/ARCHITECTURE.md
index 60595ea..24a6b42 100644
--- a/.github/ARCHITECTURE.md
+++ b/.github/ARCHITECTURE.md
@@ -254,7 +254,7 @@ PR / Feature Branch          Push to main              Tag v*
 
 On the Azure DevOps agent:
 
-1. Agent picks the best available Node handler: `Node24_1` → `Node20_1` → `Node20` (fallback)
+1. Agent picks the best available Node handler: `Node24` → `Node20_1` → `Node20` (fallback)
 2. Agent runs `tasks/<task>/dist/index.js`
 3. `index.ts` calls `task-runner.ts` → `run()`
 4. Task-runner reads inputs via `tl.getInput()`, executes logic, sets outputs via `tl.setVariable()`
diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index e852029..0d57eaa 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -69,7 +69,7 @@ Every task follows the same pattern:
 ### task.json
 
 Each task has a `task.json` defining its Azure DevOps contract:
-- Must include both `Node24_1` (primary), `Node20_1`, and `Node20` (fallback) in `execution`
+- Must include `Node24` (primary), `Node20_1`, and `Node20` (fallback) in `execution`, plus a `minimumAgentVersion` of `3.224.1`
 - Task `id` is a stable GUID (never changes)
 - Task `Major` version only bumps for breaking YAML contract changes
 - `Minor` and `Patch` are stamped by CI via inline `jq` in the workflow YAML
@@ -123,7 +123,7 @@ vi.mock('@alcops/core', async (importOriginal) => {
 
 ## Adding a New Task
 
-1. Create `tasks/<task-name>/task.json` — unique GUID, Node24_1 + Node20_1 + Node20 handlers
+1. Create `tasks/<task-name>/task.json` — unique GUID, Node24 + Node20_1 + Node20 handlers, `minimumAgentVersion` `3.224.1`
 2. Create `tasks/<task-name>/src/index.ts` (calls `run()`, guards with `.catch`) and `src/task-runner.ts` (reads inputs → calls `@alcops/core` → sets outputs)
 3. Add the task name to the `tasks` array in `esbuild.config.mjs`
 4. Add entries in `vss-extension.json` `files` and `contributions` arrays (and `vss-extension.dev.json`)
@@ -145,7 +145,7 @@ TypeScript and vitest both use the `@shared/*` alias for imports from `shared/`:
 
 ## Common Pitfalls
 
-- **Missing Node handler**: every `task.json` needs `Node24_1`, `Node20_1`, and `Node20` execution entries
+- **Missing/invalid Node handler**: every `task.json` needs `Node24`, `Node20_1`, and `Node20` execution entries (note: `Node24_1` is NOT a valid handler name — the correct key is `Node24`). Also set `minimumAgentVersion` `3.224.1` so old agents get a clear error.
 - **Shared modules aren't runtime-shared**: `shared/` helpers and `@alcops/core` are bundled into each task by esbuild. No `node_modules` sharing at runtime.
 - **Logic lives in `@alcops/core`, not here**: TFM detection, NuGet download, ZIP/PE parsing are all in the external package. Wrappers must stay thin — don't reimplement or duplicate core's validation (e.g. valid TFM lists) in the wrapper.
 - **Output variables need `isOutput: true`**: the 4th argument to `tl.setVariable()` must be `true` for downstream tasks to read the value
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d265097..804f6ed 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -71,7 +71,7 @@ npx vitest --watch                        # Watch mode
 
 ### Adding a New Task
 
-1. Create `tasks/<task-name>/task.json` with a unique GUID, Node24_1 + Node20_1 + Node20 handlers
+1. Create `tasks/<task-name>/task.json` with a unique GUID, Node24 + Node20_1 + Node20 handlers, and `minimumAgentVersion` `3.224.1`
 2. Create `tasks/<task-name>/src/index.ts` (entry point) and `src/task-runner.ts` (orchestrator)
 3. Add task to `esbuild.config.mjs` `tasks` array
 4. Add task to `vss-extension.json` `files` and `contributions` arrays
@@ -219,5 +219,5 @@ Before submitting a PR:
 - [ ] `.vsix` packages (`npm run package`)
 - [ ] New code has tests (TDD — write tests first)
 - [ ] Shared module changes tested across all affected tasks
-- [ ] `task.json` has `Node24_1`, `Node20_1`, and `Node20` execution handlers
+- [ ] `task.json` has `Node24`, `Node20_1`, and `Node20` execution handlers (not `Node24_1`) and `minimumAgentVersion` `3.224.1`
 - [ ] No secrets or credentials in source code
diff --git a/README.md b/README.md
index 89ed91a..0942ae7 100644
--- a/README.md
+++ b/README.md
@@ -115,6 +115,34 @@ Download ALCops code analyzers with automatic TFM detection.
 | `outputDir` | Full path to extracted analyzer DLLs directory |
 | `files` | Semicolon-separated list of analyzer DLL paths |
 
+## Troubleshooting
+
+### "A supported task execution handler was not found ... not compatible with your current operating system"
+
+Despite mentioning the operating system, this Azure DevOps error is **not** about your OS.
+It means your build agent is **too old** to recognize any of the task's Node execution
+handlers. The tasks ship `Node24`, `Node20_1`, and `Node20` handlers and require an agent
+of at least **v3.224.1** (the release that introduced the Node 20 handler).
+
+Fix it with any of the following:
+
+- **Upgrade the agent.** For self-hosted agents, update to the latest 3.x or 4.x agent.
+  Microsoft-hosted agents are always current. Self-hosted agents auto-update within a
+  major version but **not** across majors (v2→v3, v3→v4 require a manual upgrade).
+- **Install a newer Node runner on the agent** by adding the
+  [`NodeTaskRunnerInstaller@0`](https://learn.microsoft.com/azure/devops/pipelines/tasks/reference/node-task-runner-installer-v0)
+  task before the ALCops task:
+
+  ```yaml
+  - task: NodeTaskRunnerInstaller@0
+    inputs:
+      runnerVersion: 20
+  ```
+
+- **On-premises Azure DevOps Server:** ensure the server (and its bundled agent) is recent
+  enough. Servers older than the agent v3.224.1 baseline cannot run these tasks; upgrade
+  the server or use the `NodeTaskRunnerInstaller@0` workaround above.
+
 ## Development
 
 ### Prerequisites
diff --git a/esbuild.config.mjs b/esbuild.config.mjs
index ebc5ced..55c7e76 100644
--- a/esbuild.config.mjs
+++ b/esbuild.config.mjs
@@ -15,7 +15,7 @@ const sharedOptions = {
     bundle: true,
     format: 'cjs',
     platform: 'node',
-    target: 'node24',
+    target: 'node20',
     sourcemap: !isProduction,
     minify: isProduction,
     logLevel: 'info',
diff --git a/tasks/detect-tfm-bc-artifact/task.json b/tasks/detect-tfm-bc-artifact/task.json
index 108f340..cc84eb7 100644
--- a/tasks/detect-tfm-bc-artifact/task.json
+++ b/tasks/detect-tfm-bc-artifact/task.json
@@ -13,6 +13,7 @@
         "Minor": 0,
         "Patch": 0
     },
+    "minimumAgentVersion": "3.224.1",
     "instanceNameFormat": "ALCops Detect TFM from BC Artifact",
     "inputs": [
         {
@@ -35,14 +36,15 @@
         }
     ],
     "execution": {
-        "Node24_1": {
+        "Node24": {
             "target": "dist/index.js"
         },
         "Node20_1": {
             "target": "dist/index.js"
         },
-		"Node20": {
-			"target": "dist/index.js"
-		}
-	}
+        "Node20": {
+            "target": "dist/index.js"
+        }
+    }
 }
+
diff --git a/tasks/detect-tfm-marketplace/task.json b/tasks/detect-tfm-marketplace/task.json
index 9c800ef..fcc9741 100644
--- a/tasks/detect-tfm-marketplace/task.json
+++ b/tasks/detect-tfm-marketplace/task.json
@@ -13,6 +13,7 @@
         "Minor": 0,
         "Patch": 0
     },
+    "minimumAgentVersion": "3.224.1",
     "instanceNameFormat": "ALCops Detect TFM from VS Marketplace",
     "inputs": [
         {
@@ -51,14 +52,15 @@
         }
     ],
     "execution": {
-        "Node24_1": {
+        "Node24": {
             "target": "dist/index.js"
         },
         "Node20_1": {
             "target": "dist/index.js"
         },
-		"Node20": {
-			"target": "dist/index.js"
-		}
-	}
+        "Node20": {
+            "target": "dist/index.js"
+        }
+    }
 }
+
diff --git a/tasks/detect-tfm-nuget-devtools/task.json b/tasks/detect-tfm-nuget-devtools/task.json
index 0372dc2..c2d1e70 100644
--- a/tasks/detect-tfm-nuget-devtools/task.json
+++ b/tasks/detect-tfm-nuget-devtools/task.json
@@ -13,6 +13,7 @@
         "Minor": 0,
         "Patch": 0
     },
+    "minimumAgentVersion": "3.224.1",
     "instanceNameFormat": "ALCops Detect TFM from NuGet DevTools",
     "inputs": [
         {
@@ -35,14 +36,15 @@
         }
     ],
     "execution": {
-        "Node24_1": {
+        "Node24": {
             "target": "dist/index.js"
         },
         "Node20_1": {
             "target": "dist/index.js"
         },
-		"Node20": {
-			"target": "dist/index.js"
-		}
-	}
+        "Node20": {
+            "target": "dist/index.js"
+        }
+    }
 }
+
diff --git a/tasks/download/task.json b/tasks/download/task.json
index 1df928e..369be5d 100644
--- a/tasks/download/task.json
+++ b/tasks/download/task.json
@@ -12,6 +12,7 @@
         "Minor": 0,
         "Patch": 0
     },
+    "minimumAgentVersion": "3.224.1",
     "instanceNameFormat": "ALCops Download Analyzers $(version)",
     "inputs": [
         {
@@ -87,14 +88,14 @@
         }
     ],
     "execution": {
-        "Node24_1": {
+        "Node24": {
             "target": "dist/index.js"
         },
         "Node20_1": {
             "target": "dist/index.js"
         },
-		"Node20": {
-			"target": "dist/index.js"
-		}
-	}
-}
\ No newline at end of file
+        "Node20": {
+            "target": "dist/index.js"
+        }
+    }
+}
diff --git a/tasks/install-analyzers/task.json b/tasks/install-analyzers/task.json
index 12017ab..c4553c9 100644
--- a/tasks/install-analyzers/task.json
+++ b/tasks/install-analyzers/task.json
@@ -13,6 +13,7 @@
         "Minor": 0,
         "Patch": 0
     },
+    "minimumAgentVersion": "3.224.1",
     "instanceNameFormat": "ALCops Install Analyzers $(version)",
     "inputs": [
         {
@@ -94,14 +95,15 @@
         }
     ],
     "execution": {
-        "Node24_1": {
+        "Node24": {
             "target": "dist/index.js"
         },
         "Node20_1": {
             "target": "dist/index.js"
         },
-		"Node20": {
-			"target": "dist/index.js"
-		}
-	}
+        "Node20": {
+            "target": "dist/index.js"
+        }
+    }
 }
+
diff --git a/tests/scaffold.test.ts b/tests/scaffold.test.ts
index 96f19e1..a6fe835 100644
--- a/tests/scaffold.test.ts
+++ b/tests/scaffold.test.ts
@@ -53,9 +53,15 @@ describe('scaffold: task.json files', () => {
 			const taskJson = JSON.parse(fs.readFileSync(taskJsonPath, 'utf-8'));
 			expect(taskJson.id).toBeTruthy();
 			expect(taskJson.name).toBeTruthy();
-			expect(taskJson.execution).toHaveProperty('Node24_1');
+			expect(taskJson.execution).toHaveProperty('Node24');
 			expect(taskJson.execution).toHaveProperty('Node20_1');
 			expect(taskJson.execution).toHaveProperty('Node20');
+			// Guard against the invalid handler name reappearing (Node24_1 is not a
+			// recognized Azure Pipelines handler; the correct key is Node24).
+			expect(taskJson.execution).not.toHaveProperty('Node24_1');
+			// minimumAgentVersion gives old agents a clear error instead of the cryptic
+			// "supported task execution handler was not found" message.
+			expect(taskJson.minimumAgentVersion).toBe('3.224.1');
 		});
 
 		it(`should have src/index.ts for ${taskDir}`, () => {