--- a/devtools/client/debugger/new/panel.js
+++ b/devtools/client/debugger/new/panel.js
@@ -45,17 +45,17 @@ DebuggerPanel.prototype = {
   _selectors: function() {
     return this.panelWin.Debugger.selectors;
   },
 
   getFrames: function() {
     let frames = this._selectors().getFrames(this._getState());
 
     // frames is an empty array when the debugger is not paused
-    if (!frames.toJS) {
+    if (!frames || !frames.toJS) {
       return {
         frames: [],
         selected: -1
       }
     }
 
     frames = frames.toJS();
     const selectedFrame = this._selectors().getSelectedFrame(this._getState());

--- a/devtools/client/debugger/new/test/mochitest/browser_dbg-console.js
+++ b/devtools/client/debugger/new/test/mochitest/browser_dbg-console.js
@@ -22,13 +22,16 @@ function getSplitConsole(dbg) {
       let jsterm = toolbox.getPanel("webconsole").hud.jsterm;
       resolve(jsterm);
     });
   });
 }
 
 add_task(function* () {
   Services.prefs.setBoolPref("devtools.toolbox.splitconsoleEnabled", true);
-  const dbg = yield initDebugger("doc-script-switching.html");
+  const dbg = yield initDebugger("data:text/html;charset=utf-8,");
 
-  yield getSplitConsole(dbg);
+  const jsterm = yield getSplitConsole(dbg);
   ok(dbg.toolbox.splitConsole, "Split console is shown.");
+
+  info("Evaluating a script in the console");
+  yield jsterm.execute("1+1");
 });

--- a/devtools/client/debugger/new/test/mochitest/head.js
+++ b/devtools/client/debugger/new/test/mochitest/head.js
@@ -296,17 +296,18 @@ function createDebuggerContext(toolbox) 
  * @memberof mochitest
  * @param {String} url
  * @param {Array} sources
  * @return {Promise} dbg
  * @static
  */
 function initDebugger(url, ...sources) {
   return Task.spawn(function* () {
-    const toolbox = yield openNewTabAndToolbox(EXAMPLE_URL + url, "jsdebugger");
+    url = url.startsWith("data:") ? url : EXAMPLE_URL + url;
+    const toolbox = yield openNewTabAndToolbox(url, "jsdebugger");
     return createDebuggerContext(toolbox);
   });
 }
 
 window.resumeTest = undefined;
 /**
  * Pause the test and let you interact with the debugger.
  * The test can be resumed by invoking `resumeTest` in the console.