The ability to change extra fees has been restricted for any fee which has already been disbursed.
If it has been disbursed, you can not delete it, or change its value or change the owner associated with it. You can change the date or the description, as this does not invalidate the disbursement.
If you need to delete the fee or change its value, you will have to delete the associated disbursement first, and then recreate the disbursement again.
This brings extra fees in line with standard transactions in the cashbook which already have similar restrictions. It stops people from inadvertently affecting the integrity of their disbursement transactions and the owner reports.
When editting an extra fee, you can also see who it was disbursed to and when.