Hello, Suraj Mandal,
We kindly request that you update the theme, install the latest patches https://www.8theme.com/documentation/docs/how-to-use-xstore-patcher/ , and clear the cache. Should the issue persist, please provide us with access to the site.
To grant WP-Admin access, please proceed to create a new user account with an administrator role through your WordPress Dashboard. Once the account is established, you may securely transmit the username and password to us via the Private Content section designated for this purpose.
Best Regards,
8Theme’s Team