These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Epic Fail: Wizards of the Coast is utterly infamous for their editing problems. While they are good at a cursory glance, double-checking any Dungeons and Dragons book they've ever published will reveal tons of errors. Most prominent in 3rd edition Dungeons and Dragons books, almost to the point of They Just Didn't Care levels.
The infamous forum crashes during the 3.5-4E transition. Likewise, the errata for Tome of Battle.