Sorry for the delay in my reply.
Anyway.
I had to replace all [Serializable] with

[DataContract]

. I'm not sure how this affects serialization since I usually use

[DataContract]

together with

[DataMember]

when I build WCF services.
Next was to change the Atlas class in the constructor

public Atlas (string path, TextureLoader textureLoader)

.
using

Microsoft.Xna.Framework.TitleContainer.OpenStream(path);

to get a stream since UWP no longer seems to support strings as a builder parameter.
I still haven't been able to perform an exhaustive test so I'm not sure if this will fail at runtime, but in principle it works.

Hello.
I've been trying to integrate Spine into a Monogame project on UWP.
I did it but I had to slightly change some lines of code in the runtime
Are there plans to support UWP in the future?
If not, are there plans to stop supporting Monogame?
Thank you for your answers.

@Pharan thank you very much for your reply.

Anyway, it's easier for you to install or try out the spine-unity runtime by using the unitypackage download.
Spine Unity Download

I do not know why I had not found that link.
This seems to work very well

Sorry for my English.
I plan to acquire a spine license.
I've been trying to import the sample project available in github, however all I get are console errors like the following:
Rebuilding Library because the asset database could not be found!

A meta data file (.meta) exists but its asset 'Assets/Gizmos' can't be found. When moving or deleting files outside of Unity, please ensure that the corresponding .meta file is moved or deleted along with it.

Assertion failed: Removing Assets/Gizmos because the asset does not exist
Assets/Examples/Scripts/Sample Components/SkeletonAnimationMulti/SkeletonAnimationMulti.cs(10,26): error CS0234: The type or namespace name Animation' does not exist in the namespaceSpine'. Are you missing an assembly reference?

etc...

any ideas?
I await your comments