Well they have have banned about everything else so now China is taking on time-travel, that's right folks I said time-travel. In a response to an increase in movies and TV series that feature time-travel, the country decided that history is not represented well and thus all such projects are no longer allowed.
Here is a translation of the statement: "The time-travel drama is becoming a hot theme for TV and films. But its content and the exaggerated performance style are questionable. Many stories are totally made-up and are made to strain for an effect of novelty. The producers and writers are treating the serious history in a frivolous way, which should by no means be encouraged anymore." In a nut shell it sounds like the problem isn't necessarily with time-travel, but with movies that place modern characters together with historical figures, China finds the whole thing offensive. The result of time-travel is usually comical and at times makes some awesome science fiction movies, time-travel it is also widely used by most SciFi TV series at some point or another. This doesn't mean that movies about historical figures can't be made, they just can't be inaccurate or represent China's heroes poorly.