Unclear error message when attempting to modify player data

When attempting to modify the player data, which is not possible, the game simply says "Unable to modify player data". This message does not make it clear that this is intentional design, and insteads leads some (MC-171678, MC-226615) including myself to believe that player data is normally editable but that there is an issue with that particular command that the user inputted. Perhaps something like "Player data is not editable" would be more fitting.