XenForo 2.2.6 included support for YouTube embeds which contain a playlist ID which allows an embedded video to be viewed within the context of the playlist it is part of. While this was working perfectly fine, YouTube seemingly made a change yesterday which prevented all YouTube embeds from displaying because many of them would have had an empty list parameter in the embed URL.

This only affects customers who have already upgraded to XenForo 2.2.6 or XenForo 2.2.6 Patch 1. XenForo 2.2.6 Patch 2 resolves this issue.

XenForo 2.2.6 Patch 1 Released​

Shortly after releasing 2.2.6, we became aware of a issue that may prevent user upgrade payments for legacy (XenForo 1.x-based) subscriptions from being processed. This only affects user upgrade subscriptions that were setup when the site was running XenForo 1.x and are still active. XenForo 2.2.6 Patch 1 resolves this issue.