Minecarft Worlds can not be imported to Realms (Bedrock)

Hi agian I believe I have found a bug where worlds cannot be exported. And I have been trying for quite sometime to put back up world's on my realm it's show it's ready to be imported. Once that it goes to initialize changes then after to 4-6 minutes it says it has an error. Altough I don't have a screen shot of the problem but eventually I will share you the screen shot. With the problem. Pls reply ASAP.