Please see this link you can register for free to view it, this happened after a member have post a link of some youtube video.
I have last versions of wpForo and wpForo Embeds addon.
Also i have updated the child theme files to latest as soon i did update of wpForo.
It seems there is some issue with the link that the user's pasted. Please change the role of the user with info[at]gvectors.com email address to admin and let us know we'll check and provide some solution for you.
Sorry but i cant do that, i will look in database what is with link and edit it from there cause all buttons not work in topic.
I have solved there were 2 links of same video and some google link with redirect, i have edited and it worked.