diff --git a/src/vs/workbench/api/browser/mainThreadExtensionService.ts b/src/vs/workbench/api/browser/mainThreadExtensionService.ts
index 8bbedafd7ae..e918f18faf2 100644
--- a/src/vs/workbench/api/browser/mainThreadExtensionService.ts
+++ b/src/vs/workbench/api/browser/mainThreadExtensionService.ts
@@ -15,7 +15,7 @@ import { Action } from 'vs/base/common/actions';
 import { IWorkbenchExtensionEnablementService, EnablementState } from 'vs/workbench/services/extensionManagement/common/extensionManagement';
 import { areSameExtensions } from 'vs/platform/extensionManagement/common/extensionManagementUtil';
 import { IHostService } from 'vs/workbench/services/host/browser/host';
-import { IExtensionsWorkbenchService } from 'vs/workbench/contrib/extensions/common/extensions';
+import { IExtension, IExtensionsWorkbenchService } from 'vs/workbench/contrib/extensions/common/extensions';
 import { CancellationToken } from 'vs/base/common/cancellation';
 import { ILocalExtension } from 'vs/platform/extensionManagement/common/extensionManagement';
 import { ExtensionActivationReason } from 'vs/workbench/api/common/extHostExtensionActivator';
@@ -106,14 +106,18 @@ export class MainThreadExtensionService implements MainThreadExtensionServiceSha
 
 	private async _handleMissingNotInstalledDependency(extension: IExtensionDescription, missingDependency: string): Promise<void> {
 		const extName = extension.displayName || extension.name;
-		const dependencyExtension = (await this._extensionsWorkbenchService.queryGallery({ names: [missingDependency] }, CancellationToken.None)).firstPage[0];
+		let dependencyExtension: IExtension | null = null;
+		try {
+			dependencyExtension = (await this._extensionsWorkbenchService.queryGallery({ names: [missingDependency] }, CancellationToken.None)).firstPage[0];
+		} catch (err) {
+		}
 		if (dependencyExtension) {
 			this._notificationService.notify({
 				severity: Severity.Error,
 				message: localize('uninstalledDep', "Cannot activate the '{0}' extension because it depends on the '{1}' extension, which is not installed. Would you like to install the extension and reload the window?", extName, dependencyExtension.displayName),
 				actions: {
 					primary: [new Action('install', localize('install missing dep', "Install and Reload"), '', true,
-						() => this._extensionsWorkbenchService.install(dependencyExtension)
+						() => this._extensionsWorkbenchService.install(dependencyExtension!)
 							.then(() => this._hostService.reload(), e => this._notificationService.error(e)))]
 				}
 			});