1. Open a sub-page, e.g. search engines -- URL changes to /searchEngines.
2. While the sub-page is opening, open a sub-page in a different section, e.g. manage profile. This cancels the first sub-page animation. URL changes to /manageProfile
3. After the transition ends, use the browser back button to go back to /searchEngines.

Expected: Search engines section opens.
Actual: Blank page. Pressing Back again takes you to a broken main page (some sections are missing).

This is hard to trigger without console hacking (set EXPAND_DURATION=2000) thus Pri-3.