I uploaded my world with custom entities on it to a realm, when I joined the realm, none of the custom entities transferred, however the vanilla mob resource and behavior packs worked just fine. The packs use version 1.8 and i have changed the UUID's multiple times.
Steps to reproduce:
Create a world with a custom entity addon (I use MCPEDL.com)
Make sure the entity works on a normal world (Use Experimental gameplay)
Upload the world to a Realm.
Check to see if the custom entity can be spawned.
Linked issues
is duplicated by 19
MCPE-46287
Realm keeps disabling custom addons
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MCPE-48607
Simple furnace recipe addon does not work on realms
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MCPE-49002
Realms: Custom blocks and Items no longer show up when uploaded
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MCPE-50794
Addons not working on realms
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MCPE-50868
Custom Blocks/Items & Recipes not working on Realms
Resolved
Comments 5
Please bear in mind that certain Experimental features in worlds may not work as expected when uploaded to Realms.
I found a work around for this issue, after I uploaded my world to realms on Windows 10, I downloaded the world to a different device (Xbox One) and when I looked at the resource and behavior packs, they got deactivated, so i activated them again on Xbox and uploaded to realms again. This allowed the Custom entities to appear properly on the realm.
I'm getting a similar issue but different scenario. My realm as of this morning didn't have any custom resources. I uploaded my first resource with the steps below, no issues:
Download resource and import to MC Windows 10
Download copy of realm and apply resource
Upload world back to realm with resource
However when I attempted adding another resource nothing seems to work as you mentioned. The first resource remains there and I cannot get the second one to apply. Whenever I download the realm again it shows both resources, but again, only the first one is activated.
EDIT: Also to note, I cannot remove resources from the Realm. There's no option in the settings and whenever I download an older backup the resources still come with the export.
EDIT 2: I tried your solution but on iOS instead of XBox and had no luck. Will try again on my XBox One later today.
EDIT 3: XBox One trick worked. Downloaded the realm and enabled the resources then uploaded it back and everything is proper.
Unless there has been undocumented change for Realms, this may be working as intended. Realms do not support Experimental Gameplay or Education Edition features.