diff --git a/CHANGELOG.md b/CHANGELOG.md
index 32b3d8161..d13120eb5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ The format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 
+- **fix(tui): rename ActorSelectionOverlay._render to _refresh_display (issue #11039)** — `ActorSelectionOverlay._render()` shadows Textual's `Widget._render()` which must return a `Strip`. In textual >=1.0, layout calls `get_content_height()` → `self._render()` → gets `None` → `AttributeError: 'NoneType' object has no attribute 'get_height'`. Renamed the method to `_refresh_display()` and updated all four internal call sites (`show()`, `move_up()`, `move_down()`, `set_search()`) to use the new name.
+
 - **`task-implementor` posts work-started notification comments** (#11031): Both
   the `issue_impl` and `pr_fix` procedures now post an informational "work
   started" comment to the Forgejo issue/PR before beginning implementation.
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index 59a6ba5bf..8f209a916 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -42,4 +42,5 @@ Below are some of the specific details of various contributions.
 * HAL 9000 has contributed database resource types (PostgreSQL, SQLite) with transaction-based sandbox strategy: implemented ``DatabaseResourceHandler`` providing full CRUD operations (`read`, `write`, `delete`, `list_children`) and connection validation with automatic credential masking for PostgreSQL and SQLite backends. Includes ``TransactionSandbox`` infrastructure wired into ``SandboxFactory``, BDD test coverage in ``features/database_resources.feature``, and Robot Framework integration tests in ``robot/database_resources.robot`` (PR #10591 / issue #8608, Epic #8568).
 * HAL 9000 has contributed the agents plan rollback command (PR #8674 / issue #8557): implemented checkpoint-based plan state restoration with the `agents plan rollback <plan-id> [<checkpoint-id>]` CLI command as part of Epic #8493, enabling plans to be restored to previous checkpoints, discarding post-checkpoint decisions, and resuming execution from the rolled-back state. Supported by `--yes/-y`, `--to-checkpoint`, and `--format/-f` flags. Includes comprehensive BDD test coverage (>= 97%) for rollback, decision discarding, and plan resume functionality.
 * HAL 9000 has contributed the PyYAML security upgrade (PR #11012 / issue #9055): added `pyyaml>=6.0.3` dependency constraint to address known YAML parsing vulnerabilities.
-* HAL 9000 has contributed the A2A module rename standardization BDD tests (PR #10583 / issue #8615): comprehensive Behave test suite validating that all 22 A2A symbols are properly exported from `cleveragents.a2a`, no legacy ACP references remain in the module source, and documentation uses correct A2A naming conventions — fixing inline imports, unused behave symbols, cross-scenario context dependencies, and missing type annotations.
+* HAL 9000 has contributed the `ActorSelectionOverlay._render` -> `_refresh_display` rename fix (PR this session / issue #11039, Epic #8174): renamed `_render()` method to `_refresh_display()` to avoid shadowing Textual's `Widget._render()`, fixing a crash in textual >=1.0 where `get_content_height()` would receive `None` and raise `AttributeError: 'NoneType' object has no attribute 'get_height'`.
+* HAL 9000 has contributed the A2A module rename standardization BDD tests (PR #10583 / issue #8615): comprehensive Behave test suite validating that all 22 A2A symbols are properly exported from `cleveragents.a2a`, no legacy ACP references remain in the module source, and documentation uses correct A2A naming conventions - fixing inline imports, unused behave symbols, cross-scenario context dependencies, and missing type annotations.
\ No newline at end of file
diff --git a/src/cleveragents/tui/widgets/actor_selection_overlay.py b/src/cleveragents/tui/widgets/actor_selection_overlay.py
index d515924d8..fd27c1b3d 100644
--- a/src/cleveragents/tui/widgets/actor_selection_overlay.py
+++ b/src/cleveragents/tui/widgets/actor_selection_overlay.py
@@ -145,7 +145,7 @@ class ActorSelectionOverlay(_StaticBase):
         self._confirmed = False
         self._selected_actor = None
         self._visible = True
-        self._render()
+        self._refresh_display()
 
     def hide(self) -> None:
         """Hide the overlay and clear its content."""
@@ -161,14 +161,14 @@ class ActorSelectionOverlay(_StaticBase):
         if not self._filtered_actors:
             return
         self._selected_index = (self._selected_index - 1) % len(self._filtered_actors)
-        self._render()
+        self._refresh_display()
 
     def move_down(self) -> None:
         """Move the selection cursor down by one position (wraps)."""
         if not self._filtered_actors:
             return
         self._selected_index = (self._selected_index + 1) % len(self._filtered_actors)
-        self._render()
+        self._refresh_display()
 
     # ------------------------------------------------------------------
     # Search / filter
@@ -191,7 +191,7 @@ class ActorSelectionOverlay(_StaticBase):
         else:
             self._filtered_actors = list(self._actors)
         self._selected_index = 0
-        self._render()
+        self._refresh_display()
 
     # ------------------------------------------------------------------
     # Confirmation
@@ -215,10 +215,10 @@ class ActorSelectionOverlay(_StaticBase):
         return actor
 
     # ------------------------------------------------------------------
-    # Internal rendering
+    # Internal display refresh
     # ------------------------------------------------------------------
 
-    def _render(self) -> None:
+    def _refresh_display(self) -> None:
         content = render_actor_selection(
             self._filtered_actors,
             self._selected_index,