While an outright ban never occurred, the movie did receive some censorship. Germany has fairly strict laws when it comes to blood and violence in motion pictures, but "Terrifier 2" was allowed to be released uncensored in German movie theaters.
Terrifier 2 has skipped UK cinemas after it was deemed to be too extreme, but it is now available to rent on Amazon Prime Video - plus you can get your hands on the DVD or Blu-ray if you really wanted to.