The sidebar in the project editor that lists the main files for your app can be hidden from view if the little arrow above it is clicked.
If you have lost the sidebar, you should be able to reveal it again by doing the following:
- Expand your browser window.
- At the top-left corner of the editor, look for the blue double arrow
- Click this button to display the sidebar.
If you expand your browser window and still cannot see the little arrow:
- There may be a setting enabled in your browser that is preventing it from displaying.
- To check for this, try opening a new incognito (or private) browser window and then open the project editor.
- If you see the sidebar in the incognito window, then you will most likely be able to see the sidebar in a non-incognito window if you clear your browser cache.