Hi all! I am trying to update my macbook air 2018 from macOs mojave to macOs catalina. The update downloads without any issues but than the error displays and it says that it is impossible to define the version of macOs catalina and i have to start downloading the update again. What can I do with that? I am trying to install the update for the third time and when i tryed to do it 2 times there were errors. Thank you!