hot fix

jupyterlab/lab.html

@@ -55,7 +55,7 @@ Distributed under the terms of the Modified BSD License.
    * Get the plugins for an entry point.
    */
   var getEntryPoint = function (entryPoint) {
-    let plugins = loader.require(entryPoint);
+    var plugins = loader.require(entryPoint);
     try {
       plugins = loader.extractPlugins(plugins);
     } catch (err) {

src/running/index.ts

@@ -214,7 +214,7 @@ class RunningSessions extends Widget {
       promises.push(terminals.refreshRunning());
     }
     promises.push(sessions.refreshRunning());
-    return Promise.all(promises);
+    return Promise.all(promises).then(() => void 0);
   }
 
   /**