I've been seeing the same issue on the Nintendo Switch too when attempting to join a Realms server with over 60 MBs of add-ons that need to be downloaded.
One thing I did notice too though is that I could download the world from the Realms server and run it locally from my PC and then attempting to join from the Nintendo Switch still hits the same issue.
Additionally, I've tried playing with the order and selection of add-ons to see what is causing it myself (since the error message simply shows the icon for the highest (top) add-on in the list even after removing the top one several times in a row. Additionally, the world + add-ons was working and then after either changing the order of the add-ons OR adding a new add-on, the Nintendo Switch loses the ability to load the world anymore and crashes completely out of the game. I then tried to remove the add-on I added, but even after that it still would not load indicating that something had essentially corrupted the data necessary to load the world because the world and add-ons were the same as before, but the actions taken since point A and point B now cause the world to be unable to load and crash Minecraft. I will note that even though my Nintendo Switch is having this issue, my PC with over 64 GB of RAM is having no issue whatsoever throughout all of these attempts.
What I'm going to say next might be related, but might be separate, I've noticed that occasionally the de-activation of add-ons doesn't remove everything from that add-on especially if it's still in my inventory (like guidebooks and tutorials), but this could simply be a red herring when tracking down this issue.
bicole39
I've been seeing the same issue on the Nintendo Switch too when attempting to join a Realms server with over 60 MBs of add-ons that need to be downloaded.
One thing I did notice too though is that I could download the world from the Realms server and run it locally from my PC and then attempting to join from the Nintendo Switch still hits the same issue.
Additionally, I've tried playing with the order and selection of add-ons to see what is causing it myself (since the error message simply shows the icon for the highest (top) add-on in the list even after removing the top one several times in a row. Additionally, the world + add-ons was working and then after either changing the order of the add-ons OR adding a new add-on, the Nintendo Switch loses the ability to load the world anymore and crashes completely out of the game. I then tried to remove the add-on I added, but even after that it still would not load indicating that something had essentially corrupted the data necessary to load the world because the world and add-ons were the same as before, but the actions taken since point A and point B now cause the world to be unable to load and crash Minecraft. I will note that even though my Nintendo Switch is having this issue, my PC with over 64 GB of RAM is having no issue whatsoever throughout all of these attempts.
What I'm going to say next might be related, but might be separate, I've noticed that occasionally the de-activation of add-ons doesn't remove everything from that add-on especially if it's still in my inventory (like guidebooks and tutorials), but this could simply be a red herring when tracking down this issue.