Hello, @ByLegenS,
Try the solution from this topic – https://www.8theme.com/topic/the-package-could-not-be-installed-pclzip_err_bad_format-10-unable-to-find-2/ or do the update manually via FTP – https://xstore.helpscoutdocs.com/article/63-theme-update
Regards 8Themes Team.
