Try running the installation with administrator rights, and also disable your antivirus.
I can't try it yet, but you should try it, maybe it will help?
Because after installing the update, it deletes all files from the "resources" folder. Before the installation, it was 4.5 gigabytes, after, it was 1 byte.
the same 1.2 DL version. DMM version and Dlsite version - no different.
※2016/08/05 バージョン1.2に差し替え(シーンを1つ追加)
※2015/09/12 バージョン1.1に差し替え(ヒント機能、回想機能、シーンを1つ追加)
※2015/08/26 商品をタイプBに変更 - Change to type B T_T