Hello,
1/ Please do recommendations from this topic – https://www.8theme.com/topic/cant-save-changes-in-xstore-theme-customizer/#post-326259 2/ Provide temporary wp-admin access, so we can take a closer look. Create an account via Dashboard (Users > Add new) with administrator role http://prntscr.com/s3rc9m > provide us with username and password via the Private Content area http://prntscr.com/s5mao7 You can use any email for it.
Regards
