From a workaround posted on vBulletin.org:
If you are not already aware the latest version of Chrome browser (Version 54.0.2840.71, possibly others) has introduced a bug or incompatibility with the version of CKEditor used in VB 4.x.
If a user attempts to use the "Reply With Quote" feature on an existing post and begins to type their reply under the existing quote without hitting the Enter key first, the space bar will not work.
The issue is talked about on vBulletin.com here: http://www.vbulletin.com/forum/forum...rking-on-reply
If a user attempts to use the "Reply With Quote" feature on an existing post and begins to type their reply under the existing quote without hitting the Enter key first, the space bar will not work.
The issue is talked about on vBulletin.com here: http://www.vbulletin.com/forum/forum...rking-on-reply