On May 10, 2023, the OFAC issued a notice that the US Department of Treasury is initiating the annual renewal of the public-trusted certificate securing www.treasury.gov website, including OFAC sanctions list downloads. The existing certificate will be replaced on May 15, 2023 at 8PM EDT.
According to the OFAC, the process will take around 1 hour for the replacement certificate to be fully distributed worldwide. Scripts and other automated processes that download OFAC's list-related data products; browsing OFAC's website (depending on browser used and its configuration) will be affected by the action.
The OFAC’s notice can be found here.