what happens in Georgia if there are only 2 witnesses to a codicil and one of them is a beneficiary of that codicil?

If a beneficiary is also a witness, typically in Georgia the result is that the benefits which the witness/beneficiary was to receive under the Will or codicil are not received. This is because you can either be a witness or a beneficiary, but not both, and the law tends to lean towards upholding the Will. Allowing the witness/beneficiary to be a witness but not a beneficiary can allow the Will to remain valid in other respects. Disqualifying the witness/beneficiary as a witness would prevent the Will from being valid at all. Therefore, the witness/beneficiary receives nothing but is counted as a witness.