The error message, if the user don't have the right to see the upload button on mobile pages.
Associated actions - in the sentence "You don't have permission to X", where the first part of the sentence comes from("You do not have permission to $2, for the following reasons:").
This is an action that corresponds to a user right. See Special:ListGroupRights for an overview of the rights used on translatewiki.net. See Manual:User rights at MediaWiki.org for general information.
For the corresponding user right to this action,("use the simplified mobile upload system"), see:
- ("Use the upload button on mobile pages")