The most likely (but not the only) cause for this is that the champion associated with the fund is a removed record.  When a constituent record is removed, but is the current active champion for a fund, the fund itself no longer becomes editable or searching within the admin side of the database.

To resolve this, contact support and request they associated champion be reactivated.  Once the overnight task to reactivate has completed the fund will be available for searching and editing once again.