Edits cannot be made to a term if there are any publishers assigned to that term. If publishers are assigned to the term you wish to edit, you can either create a new term and move all publishers over or you can use the clone function to make edits and automatically transfer all publishers over.
To clone a term, navigate to Settings> Commission Terms and find the term you wish to change. Once you locate the term, click on the term and locate Clone Term. You will then be able to make changes to that term. You will need to click the Transfer publishers to this term’ box. Publishers require a 7-day notice to change their terms, but you can allow the change to take effect as soon as possible (pending acceptance from the publisher) by checking the Allow Early Acceptance box.