I bought an item on Code Canyon one year ago, I customized it and would like to add a lot of other customizations. I would like to know if I am allowed to sell my item, knowing that the original item has not received any updates within a year.
no, you can’t and it is never aceptable. with the permission from the orginal item author and also have to get permission from the envato support team you can create family product (as like html to wordpress) but never can’t make the same type item (as like same app).