56. Effect of nullity of registration of license contract

Where, before the expiration of the license contract the registration is declared null and void the licensee in such event not be required to make any payment to the licensor under the licence contract, and shall be entitled to reimbursement of the payments already made :

Provided that the licensor shall not be required to make any repayment, or be required to make repayment in part, to the extent of his ability to prove that such repayment would be inequitable having considerd all the circumstances and in particular whether the licensee has effectively profited from the licence.