I have over 60Gb free on my Xbox One and I keep getting this error. I've had to delete many worlds because of it, as have my kids. We aren't happy about that all all ... but I digress. What gives here? Ever since the Update Aquatic we've been getting this error. Right now my kids have zero worlds and whenever they try to do ANYTHING (store, skin, create a world) they get this error message.
The Xbox reserves some space, but 60GB seems excessive. How many worlds do you have now, and approximately how much storage do they take up? Do you have any attached external storage? If you look into the Manage Storage area, does the size of the Minecraft save data match what you calculate for your worlds?
If you try to install a new game (one of the freebies with Xbox Live for example), do you also get the message?