I found that Adobe has published the security update APSB18-24 which includes one update package "install_flash_player_3000134_ax.exe". And it is not able to be downloaded in China, the web page will be redirected to "https://helpx.adobe.com/cn/flash-player/kb/flash-player-issues-windows-10-ie.html". But if I try to use VPN to connect to America netowrk, then the download of this package will be successful.
This suggests you have Windows 10. If so, Microsoft embeds Flash Player for IE and Edge and all updates are released by Microsoft via Windows Updates. If you have Windows 10 (or 8.1), run Windows Update to update Flash Player for IE and Edge (Windows 10).
Flash Player downloads in China are available at www.flash.cn. They are not available anywhere else. While downloading from VPN in US may appear successful, Flash Player downloaded from this location will not work in China.