Newest Musescore 3.5 beta (RC Version) Installing Problem

Last week I received the announcement of the updating and I downloaded it via application itself (directly click the "download button and wait for update". This problem came up. And I downloaded directly the newest package from website and tried to install it cowering the original. The same came up. Then I deleted the old version and tried to install it. None was changed. The same windows jumps out infinitively if I push the "Retry" button so that I can't update my Musescore now. Need solution or please fix it up.