Video helps but please also post text as not everyone will click on a link with no further information. I half expected a bad site.
The problem the poster is having is that when they click on Search tab and then go back to TOC, then the TOC is blank until they hide the pane and then click TOC again.
What we don't know from the thread or the video is the version of Rh or the version of the browser. Also does this happen in other browsers?
It might be worth looking at http://www.wvanweelden.eu/articles/robohelp-patches-and-updates
See www.grainge.org for RoboHelp and Authoring tips

@petergrainge
Use the menu (bottom right) to mark the Best Answer or Highlight particularly useful replies. Found the answer elsewhere? Share it here.