diff --git a/src/vs/workbench/contrib/chat/common/chatServiceImpl.ts b/src/vs/workbench/contrib/chat/common/chatServiceImpl.ts
index d2ac621f3b5..f937415cf67 100644
--- a/src/vs/workbench/contrib/chat/common/chatServiceImpl.ts
+++ b/src/vs/workbench/contrib/chat/common/chatServiceImpl.ts
@@ -3,6 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+import { Action } from 'vs/base/common/actions';
 import { CancellationToken, CancellationTokenSource } from 'vs/base/common/cancellation';
 import { ErrorNoTelemetry } from 'vs/base/common/errors';
 import { Emitter, Event } from 'vs/base/common/event';
@@ -13,9 +14,10 @@ import { revive } from 'vs/base/common/marshalling';
 import { StopWatch } from 'vs/base/common/stopwatch';
 import { URI, UriComponents } from 'vs/base/common/uri';
 import { localize } from 'vs/nls';
-import { CommandsRegistry } from 'vs/platform/commands/common/commands';
+import { CommandsRegistry, ICommandService } from 'vs/platform/commands/common/commands';
 import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
 import { ILogService } from 'vs/platform/log/common/log';
+import { INotificationService, Severity } from 'vs/platform/notification/common/notification';
 import { Progress } from 'vs/platform/progress/common/progress';
 import { IStorageService, StorageScope, StorageTarget } from 'vs/platform/storage/common/storage';
 import { ITelemetryService } from 'vs/platform/telemetry/common/telemetry';
@@ -145,7 +147,9 @@ export class ChatService extends Disposable implements IChatService {
 		@IWorkspaceContextService private readonly workspaceContextService: IWorkspaceContextService,
 		@IChatSlashCommandService private readonly chatSlashCommandService: IChatSlashCommandService,
 		@IChatVariablesService private readonly chatVariablesService: IChatVariablesService,
-		@IChatAgentService private readonly chatAgentService: IChatAgentService
+		@IChatAgentService private readonly chatAgentService: IChatAgentService,
+		@INotificationService private readonly notificationService: INotificationService,
+		@ICommandService private readonly commandService: ICommandService,
 	) {
 		super();
 
@@ -349,6 +353,17 @@ export class ChatService extends Disposable implements IChatService {
 			const defaultAgent = this.chatAgentService.getActivatedAgents().find(agent => agent.id === defaultAgentData.id);
 			if (!defaultAgent) {
 				// Should have been registered during activation above!
+				this.notificationService.notify({
+					severity: Severity.Error,
+					message: localize('chatFailErrorMessage', "Chat failed to load. Please ensure that the GitHub Copilot Chat extension is up to date."),
+					actions: {
+						primary: [
+							new Action('showExtension', localize('action.showExtension', "Show Extension"), undefined, true, () => {
+								return this.commandService.executeCommand('workbench.extensions.action.showExtensionsWithIds', ['GitHub.copilot-chat']);
+							})
+						]
+					}
+				});
 				throw new ErrorNoTelemetry('No default agent registered');
 			}
 			const welcomeMessage = model.welcomeMessage ? undefined : await defaultAgent.provideWelcomeMessage?.(model.initialLocation, token) ?? undefined;
diff --git a/src/vs/workbench/contrib/inlineChat/test/browser/inlineChatController.test.ts b/src/vs/workbench/contrib/inlineChat/test/browser/inlineChatController.test.ts
index 057adbf7622..5bf79cc3971 100644
--- a/src/vs/workbench/contrib/inlineChat/test/browser/inlineChatController.test.ts
+++ b/src/vs/workbench/contrib/inlineChat/test/browser/inlineChatController.test.ts
@@ -58,6 +58,8 @@ import { ChatWidgetHistoryService, IChatWidgetHistoryService } from 'vs/workbenc
 import { IHoverService } from 'vs/platform/hover/browser/hover';
 import { NullHoverService } from 'vs/platform/hover/test/browser/nullHoverService';
 import { ChatVariablesService } from 'vs/workbench/contrib/chat/browser/chatVariables';
+import { ICommandService } from 'vs/platform/commands/common/commands';
+import { TestCommandService } from 'vs/editor/test/browser/editorTestServices';
 
 suite('InteractiveChatController', function () {
 	class TestController extends InlineChatController {
@@ -136,6 +138,7 @@ suite('InteractiveChatController', function () {
 			[IInlineChatService, new SyncDescriptor(InlineChatServiceImpl)],
 			[IDiffProviderFactoryService, new SyncDescriptor(TestDiffProviderFactoryService)],
 			[IInlineChatSessionService, new SyncDescriptor(InlineChatSessionServiceImpl)],
+			[ICommandService, new SyncDescriptor(TestCommandService)],
 			[IInlineChatSavingService, new class extends mock<IInlineChatSavingService>() {
 				override markChanged(session: Session): void {
 					// noop
diff --git a/src/vs/workbench/contrib/inlineChat/test/browser/inlineChatSession.test.ts b/src/vs/workbench/contrib/inlineChat/test/browser/inlineChatSession.test.ts
index 043ea8c80ab..b28ae6f4ad7 100644
--- a/src/vs/workbench/contrib/inlineChat/test/browser/inlineChatSession.test.ts
+++ b/src/vs/workbench/contrib/inlineChat/test/browser/inlineChatSession.test.ts
@@ -55,6 +55,8 @@ import { IViewsService } from 'vs/workbench/services/views/common/viewsService';
 import { TestExtensionService, TestContextService } from 'vs/workbench/test/common/workbenchTestServices';
 import { IChatAgentService, ChatAgentService, ChatAgentLocation } from 'vs/workbench/contrib/chat/common/chatAgents';
 import { ChatVariablesService } from 'vs/workbench/contrib/chat/browser/chatVariables';
+import { ICommandService } from 'vs/platform/commands/common/commands';
+import { TestCommandService } from 'vs/editor/test/browser/editorTestServices';
 
 suite('InlineChatSession', function () {
 
@@ -89,6 +91,7 @@ suite('InlineChatSession', function () {
 			[IContextKeyService, contextKeyService],
 			[IDiffProviderFactoryService, new SyncDescriptor(TestDiffProviderFactoryService)],
 			[IInlineChatSessionService, new SyncDescriptor(InlineChatSessionServiceImpl)],
+			[ICommandService, new SyncDescriptor(TestCommandService)],
 			[IInlineChatSavingService, new class extends mock<IInlineChatSavingService>() {
 				override markChanged(session: Session): void {
 					// noop