TOP.ONE has upgraded the DAI to new Multi-Collateral Dai contract version at 17:00 PM on February 11, 2020. The previous version of DAI will be changed to SAI which is no longer supported. The upgrade will complete automatically. Please note that deposited SAI will not be credited to account.
MakerDAO official supports online conversion of SAI to the new multi-mortgage DAI.
Convert SAI at: https://migrate.makerdao.com/
Thank you for your support！