Property of an estate shall be sold only subject to the confirmation of the district court, on petition of the receiver or assignee, and on such notice as the court may fix. The fees and expenses of all officers and employees shall be under the control of the court, and shall not be paid by the receiver or assignee until approved by the court. Any transfer of any property by any assignee or trustee or receiver shall be void unless the same shall have been approved by the judge of the district court before whom such matter should be pending.