Hi Roman,
Thanks for the reply and sorry for not getting back earlier.
My server is bedrock and I'm not sure if somehow this didn't allowed me to use the webNBT. I Also tried nbt editor, with the same result (not able to load the file)
Finally I used a nbt-studio tool and I was able to see the structure in the file, similar to what was expected in the web version. But there is no player block.
Also, this is a multiplayer world.
Is there something that I'm missing?
Thanks!