I cannot update my BeThem theme from 18.104.22.168 to 21.0.6 and my
Slider Revolution - Premium responsive slider
I Always have this error message :
An error occurred while updating Betheme: The archive could not be installed. This package does not contain any files.
Thanks for asking your question at Envato forum.
This is your item support
you can ask anykind of question about your purchase theme author @muffingroup at here as a comments
If they ask about purchase key then collect from Here
Still have any question open a Envato help ticket from Here
Hope this will help you https://forum.muffingroup.com/betheme/discussion/44253/can-t-update-to-version-21-0-2 to see the support team solution answer you will need to login.