Fix #38293

src/vs/workbench/parts/extensions/browser/extensionEditor.ts

@@ -479,6 +479,8 @@ export class ExtensionEditor extends BaseEditor {
 					append(this.content, scrollableContent.getDomNode());
 					this.contentDisposables.push(scrollableContent);
 				}
+			}, () => {
+				append(this.content, $('p.nocontent')).textContent = localize('noContributions', "No Contributions");
 			}));
 	}
 

src/vs/workbench/parts/extensions/node/extensionsWorkbenchService.ts

@@ -189,6 +189,7 @@ class Extension implements IExtension {
 				return this.galleryService.getManifest(this.gallery);
 			}
 			this.telemetryService.publicLog('extensions:NotFoundManifest', this.telemetryData);
+			return TPromise.wrapError<IExtensionManifest>(new Error('not available'));
 		}
 
 		return TPromise.as(this.local.manifest);