As of 1.2 the loading of the YTD has been simplified. As of version 1.2 The Ytd NO LONGER needs to be drag and dropped into mods\update\update.rpf\x64\textures\script_txds.rpf\.
Instead if you have already installed the GTAO Mansions in SP (pre 1.2) mod you need to copy and paste the YTD folder in GTAO_Mansions_In_SP from the zip into your GTAO_Mansions_In_SP (in your script folder). 
If your download GTAO Mansions in SP for the first time post 1.2 (or on update 1.2) all you need to do is copy GTAO Mansions in SP folder into scripts.