diff --git a/packages/_integrationTests/src/ExtensionApi.mts b/packages/_integrationTests/src/ExtensionApi.mts
index d06be6f92..7d048f50f 100644
--- a/packages/_integrationTests/src/ExtensionApi.mts
+++ b/packages/_integrationTests/src/ExtensionApi.mts
@@ -1,3 +1,3 @@
 export type { OnSpellCheckDocumentStep } from '../../_server/dist/api.cjs';
-export type { CSpellClient } from '../../client/dist/client/index.mjs';
-export type { ExtensionApi } from '../../client/dist/extensionApi.mjs';
+export type { CSpellClient } from '../../client/out/client/index.mjs';
+export type { ExtensionApi } from '../../client/out/extensionApi.mjs';
diff --git a/packages/client/src/configWatcher.mts b/packages/client/src/configWatcher.mts
index 9058e5570..10a201f54 100644
--- a/packages/client/src/configWatcher.mts
+++ b/packages/client/src/configWatcher.mts
@@ -1,9 +1,10 @@
 import { opMap, pipe } from '@cspell/cspell-pipe/sync';
-import { defaultConfigFilenames } from 'cspell-lib';
 import { createDisposableList } from 'utils-disposables';
 import type { Disposable, Event, Uri } from 'vscode';
 import * as vscode from 'vscode';
 
+import { defaultConfigFilenames } from './defaultConfigFilenames.mjs';
+
 export interface ConfigWatcher extends Disposable {
     on: Event<Uri>;
     onDidChangeConfig: Event<Uri>;
diff --git a/packages/client/src/defaultConfigFilenames.mts b/packages/client/src/defaultConfigFilenames.mts
new file mode 100644
index 000000000..2329e5a98
--- /dev/null
+++ b/packages/client/src/defaultConfigFilenames.mts
@@ -0,0 +1,52 @@
+export const defaultConfigFilenames = [
+    'package.json',
+    '.cspell.json',
+    'cspell.json',
+    '.cSpell.json',
+    'cSpell.json',
+    '.cspell.jsonc',
+    'cspell.jsonc',
+    '.vscode/cspell.json',
+    '.vscode/cSpell.json',
+    '.vscode/.cspell.json',
+    '.cspell.config.json',
+    '.cspell.config.jsonc',
+    '.cspell.config.yaml',
+    '.cspell.config.yml',
+    'cspell.config.json',
+    'cspell.config.jsonc',
+    'cspell.config.yaml',
+    'cspell.config.yml',
+    'cspell.config.mjs',
+    'cspell.config.cjs',
+    'cspell.config.js',
+    '.cspell.config.mjs',
+    '.cspell.config.cjs',
+    '.cspell.config.js',
+    '.cspell.yaml',
+    '.cspell.yml',
+    'cspell.yaml',
+    'cspell.yml',
+    '.config/.cspell.json',
+    '.config/cspell.json',
+    '.config/.cSpell.json',
+    '.config/cSpell.json',
+    '.config/.cspell.jsonc',
+    '.config/cspell.jsonc',
+    '.config/cspell.config.json',
+    '.config/cspell.config.jsonc',
+    '.config/cspell.config.yaml',
+    '.config/cspell.config.yml',
+    '.config/cspell.config.mjs',
+    '.config/cspell.config.cjs',
+    '.config/cspell.config.js',
+    '.config/.cspell.config.json',
+    '.config/.cspell.config.jsonc',
+    '.config/.cspell.config.yaml',
+    '.config/.cspell.config.yml',
+    '.config/.cspell.config.mjs',
+    '.config/.cspell.config.cjs',
+    '.config/.cspell.config.js',
+    '.config/cspell.yaml',
+    '.config/cspell.yml',
+] as const;
diff --git a/packages/client/src/defaultConfigFilenames.test.mts b/packages/client/src/defaultConfigFilenames.test.mts
new file mode 100644
index 000000000..a022873bb
--- /dev/null
+++ b/packages/client/src/defaultConfigFilenames.test.mts
@@ -0,0 +1,10 @@
+import { defaultConfigFilenames as cspellDefaultConfigFilenames } from 'cspell-lib';
+import { describe, expect, test } from 'vitest';
+
+import { defaultConfigFilenames } from './defaultConfigFilenames.mjs';
+
+describe('defaultConfigFilenames', () => {
+    test('defaultConfigFilenames', () => {
+        expect(new Set(defaultConfigFilenames)).toEqual(new Set(cspellDefaultConfigFilenames));
+    });
+});
diff --git a/packages/client/src/extension.mts b/packages/client/src/extension.mts
index b8a74fb6d..28594226a 100644
--- a/packages/client/src/extension.mts
+++ b/packages/client/src/extension.mts
@@ -43,21 +43,34 @@ let currLogLevel: CSpellSettings['logLevel'] = undefined;
 modules.init();
 
 export function activate(context: ExtensionContext): Promise<ExtensionApi> {
-    performance.mark('cspell_activate_start');
-    di.set('extensionContext', context);
-    const eventLogger = createEventLogger(context.globalStorageUri);
-    di.set('eventLogger', eventLogger);
-    eventLogger.logActivate();
+    try {
+        performance.mark('cspell_activate_start');
+        di.set('extensionContext', context);
+        const eventLogger = createEventLogger(context.globalStorageUri);
+        di.set('eventLogger', eventLogger);
+        eventLogger.logActivate();
 
-    setOutputChannelLogLevel();
+        setOutputChannelLogLevel();
 
-    const eIssueTracker = new vscode.EventEmitter<IssueTracker>();
-    const pIssueTracker = new Promise<IssueTracker>((resolve) => eIssueTracker.event(resolve));
+        const eIssueTracker = new vscode.EventEmitter<IssueTracker>();
+        const pIssueTracker = new Promise<IssueTracker>((resolve) => eIssueTracker.event(resolve));
 
-    activateIssueViewer(context, pIssueTracker);
-    activateFileIssuesViewer(context, pIssueTracker);
+        performance.mark('activateIssueViewer');
+        activateIssueViewer(context, pIssueTracker);
+        performance.mark('activateFileIssuesViewer');
+        activateFileIssuesViewer(context, pIssueTracker);
 
-    return _activate(context, eIssueTracker);
+        performance.mark('start_async_activate');
+        return _activate(context, eIssueTracker).catch((e) => {
+            throw activationError(e);
+        });
+    } catch (e) {
+        throw activationError(e);
+    }
+}
+
+function activationError(e: unknown) {
+    return new Error(`Failed to activate: (${performance.getLastEventName()}) ${e}`, { cause: e });
 }
 
 async function _activate(context: ExtensionContext, eIssueTracker: vscode.EventEmitter<IssueTracker>): Promise<ExtensionApi> {
@@ -65,6 +78,7 @@ async function _activate(context: ExtensionContext, eIssueTracker: vscode.EventE
     const dLogger = bindLoggerToOutput(logOutput);
 
     // Get the cSpell Client
+    performance.mark('create client');
     const client = await CSpellClient.create(context);
     context.subscriptions.push(client, logOutput, dLogger);
 
@@ -84,10 +98,13 @@ async function _activate(context: ExtensionContext, eIssueTracker: vscode.EventE
         });
     }
 
+    performance.mark('ExtensionRegEx.activate');
     ExtensionRegEx.activate(context, client);
 
     // Start the client.
+    performance.mark('start client');
     await client.start();
+    performance.mark('start IssueTracker');
     const issueTracker = new IssueTracker(client);
     di.set('issueTracker', issueTracker);
     eIssueTracker.fire(issueTracker);
@@ -112,6 +129,7 @@ async function _activate(context: ExtensionContext, eIssueTracker: vscode.EventE
         triggerGetSettings();
     }
 
+    performance.mark('createConfigWatcher');
     const configWatcher = createConfigWatcher();
     // console.log('config files: %o', await configWatcher.scanWorkspaceForConfigFiles());
     const decorator = new SpellingIssueDecorator(context, issueTracker);
@@ -125,6 +143,8 @@ async function _activate(context: ExtensionContext, eIssueTracker: vscode.EventE
         'cSpell.createCSpellTerminal': createTerminal,
     };
 
+    performance.mark('register');
+
     // Push the disposable to the context's subscriptions so that the
     // client can be deactivated on extension deactivation
     context.subscriptions.push(
@@ -161,6 +181,7 @@ async function _activate(context: ExtensionContext, eIssueTracker: vscode.EventE
         client.onBlockFile(notifyUserOfBlockedFile),
     );
 
+    performance.mark('registerCspellInlineCompletionProviders');
     await registerCspellInlineCompletionProviders(context.subscriptions).catch(() => undefined);
 
     function handleOnDidChangeConfiguration(event: vscode.ConfigurationChangeEvent) {
@@ -240,6 +261,8 @@ async function _activate(context: ExtensionContext, eIssueTracker: vscode.EventE
     const getConfigurationForDocument = <F extends ConfigurationFields>(doc: vscode.TextDocument, fields: ConfigFieldSelector<F>) =>
         client.getConfigurationForDocument(doc, fields);
 
+    performance.mark('setup Extension API');
+
     const server = {
         registerConfig,
         triggerGetSettings,
@@ -263,6 +286,7 @@ async function _activate(context: ExtensionContext, eIssueTracker: vscode.EventE
         disableCurrentLanguage: commands.disableCurrentFileType,
     } as const satisfies ExtensionApi & { getConfigurationForDocument: typeof getConfigurationForDocument };
 
+    performance.mark('activateWebview');
     activateWebview(context);
 
     performance.mark('cspell_activate_end');
diff --git a/packages/client/src/util/perf.ts b/packages/client/src/util/perf.ts
index f02ac5fa7..b21476e78 100644
--- a/packages/client/src/util/perf.ts
+++ b/packages/client/src/util/perf.ts
@@ -34,6 +34,14 @@ export class PerformanceTimeline {
         this.addEvent(event);
     }
 
+    getLastEvent(): TimeLineEvent {
+        return this.timeLine[this.timeLine.length - 1];
+    }
+
+    getLastEventName(): string {
+        return this.getLastEvent().name || '';
+    }
+
     private addEvent(event: TimeLineEvent) {
         this.timeLine.push(event);
         this.timeLineEvents.set(event.name, event);
diff --git a/packages/client/tsconfig.api.json b/packages/client/tsconfig.api.json
index 1bd352e74..fad5d3326 100644
--- a/packages/client/tsconfig.api.json
+++ b/packages/client/tsconfig.api.json
@@ -1,6 +1,7 @@
 {
     "extends": "./tsconfig.json",
     "compilerOptions": {
+        "outDir": "./out",
         "emitDeclarationOnly": true
     },
     "files": ["src/extensionApi.mts"]
diff --git a/packages/client/tsconfig.test.json b/packages/client/tsconfig.test.json
index 7275d0a67..2cacfbd3d 100644
--- a/packages/client/tsconfig.test.json
+++ b/packages/client/tsconfig.test.json
@@ -1,6 +1,7 @@
 {
     "extends": "./tsconfig.json",
     "compilerOptions": {
+        "noEmit": true,
         "module": "NodeNext",
         "moduleResolution": "NodeNext",
         "outDir": "temp/dist"