We are still using X Theme v4 for a site (https://kathystable.com). The old X theme is perfectly stable and therefore we've never had cause to update to either X or Pro.
However, the Wordpress update to 4.9 created a bug in our video backgrounds (noted in this fix to X and Pro: https://theme.co/apex/forum/t/wordpress-4-9-fix/15130). Rather than either updating to a newer version of X or restoring an older version of the site, we'd like to just go ahead and try to find a fix for this display bug, if possible.
This site gets far too much traffic to attempt an unknown theme update, and we're reluctant to even take it offline long enough to perform a site restore. Please let me know if you are aware of an edit to the site as it stands so that we might fix this without performing a more critical update.
Thanks so much!