I had this issue - blank info boxes, blank lessons about toddlers (after the latest update), and blank "actions" when I wanted a sim to interact with a toddler, as well as some items being listed as *debug*. Super frustrating.
However I followed the advice given above, from this site sims4.crinrict(dot)com/en/2014/11/codes-instead-of-text/ . The only thing that was different was that my Sims 4 files were under Electronic Arts instead of Origin games.
Hope this helps anyone who has been unable to play their game!