If you are using Windows and have problem editing the file, follow this: right-click the quoted arquive and ‘open with’ then select ‘wordpad’. Make the change from noMiner: true to ‘false’ and try to save the arquive. If you cant save it in the game folder (because you installed it in the C: directory and needs admin permission or whatever), save it in the deskot the paste/copy it to the game’s folder and allow the substituition.
Don’t delete your desktop file 'cause you will need it to disable the mining if/when needed.
Don’t forget to quit the game and start it again to apply the changes.
It should work fine then.