Twice in the final chapters of Revelation, John falls before an angel and the angel tells him to get up: “I am a fellow servant of yours and your brothers who hold the testimony of Jesus. Worship God” (19:10; 22:8-9).
It seems a simple reaffirmation of monotheism. Of course, no one worships angels. But apparently some did (Colossians 2:18), and apparently at one time it was perfectly OK. Manoah and his wife fall before an angel (Judges 13:20), and so does David (1 Chronicles 21:16). No objections from the angels there.
These scenes appear in Revelation because something has changed in the relation of angels and men. For a little while mankind was lower than the angels, and in that old time it was fine to honor them. Now humans have been elevated to share in angelic service, ultimately to be elevated above the angels (“you will judge angels,” says Paul). Instead of falling at the feet of angels, we now stand with and among them as fellow servants.