Sigma has released firmware update for its Mount Converter MC-11 EF-E and MC-11 SA-E that provides compatibility with the Sigma 70-200mm f/2.8 DG OS HSM | Sports Lens.
From Sigma:
Mount Converter MC-11 Firmware v.1.20 (EF-E) & 1.14 (SA-E)*
* Before updating the SIGMA MOUNT CONVERTER MC-11 firmware, please ensure SIGMA Optimization Pro has been updated to ver. 1.4.1 or later for Windows, and ver. 1.4.0 or later for Macintosh.
B&H carries the Sigma 70-200mm f/2.8 DG OS HSM | Sports Lens.