11 October 2020 by [Mojang] CornerHard - We're reworking the upload and download system to make it more reliable for all platforms, but in the meantime, 1.16.100 will have more accurate error messages with steps to solve the problem in some cases.
11 August 2020 by [Mojang] CornerHard - If you're still unable to upload your local Switch world to your Realm in 1.16.20, try archiving and redownloading Minecraft on your Switch. After reinstalling, you should be able to upload your world, though you'll still get the "An error has occured" dialog after the upload completes. Join your Realm and it should be updated.
23 July 2020 by [Mojang] CornerHard - Apologies for the frustrations with not being able to get your worlds off your Switch consoles! I have a fix for world upload to Realms from Switch coming in 1.16.2, though you will still see the "An error has occured" dialog despite the successful upload. If this makes your Realm completely unusable until 1.16.2, please contact Mojang Support, and they will help you with a refund or compensation.
10 July 2020 by [Mojang] Mega_Spud (Jay Wells) - Thank you for your patience while we work on this important issue. As a workaround, some players have found that they are able to use another device to upload their worlds to their Realms (such as Windows 10) - that might get you out of a fix until the bug is resolved.
1 June 2020 by [Mojang] Matt Gartzke - Hey all, the team is working to resolve this issue and will have a solution soon. Thanks for your patience! Keep your eyes on https://twitter.com/MojangStatus for updates.
26 May 2020 by [Mod] Umija5895M - Please keep comments to new and helpful information that will assist in getting this issue resolved. Voting for this issue is the best way to raise attention.