Thanks for contacting us.
You need to update the XStore theme and XStore core plugin to versions 6.3.9.1 and 2.3.9.1.
“PCLZIP_ERR_BAD_FORMAT (-10) ” problem could be caused by a few reasons:
1) You are trying to update the theme on the different domain that theme was activated (for example you activated the theme on localhost and moved it to live domain). Then you just need to go to XStore dashboard > deactivate theme and activate it using your purchase code again
2) There is no enough space on your server and archive that was downloaded for the update is broken. Make sure that you have no less than 20MB of the free space on your hosting.
You can also update the theme via FTP instead of auto-update – http://xstore.helpscoutdocs.com/article/63-theme-update
and plugin – https://xstore.helpscoutdocs.com/article/37-plugins-update Please download latest versions of the theme and Core from this page – https://www.8theme.com/downloads/
Once you do the update, the problem with activation will be solved.
If you use Massive Addons plugin it has compatibility issues with the new WP update – WPBakery Page builder (formerly Visual Composer) can’t work correctly. Either downgrade the WP to the previous version or wait for the Massive addons plugin update, when they release fix for this https://codecanyon.net/item/massive-addons-for-visual-composer/14429839/comments?page=109&filter=all#comment_24928281
