I downloaded my world, took off a resource pack, then tried to replace world on realm. replacement failed. [ Tried repeatedly ]  I tried to replace with a different world. Still would not replace.  I reset realm ant then tried to replace world. FAILED !  I closed the realm and opened a new realm. Then tried to put my world on it.  Still could not replace the starting seed with any of my worlds.   Replacing with a previous save did not work either.