So this has been happening to me all the time and I can't figure it out myself. Basically, whenever someone tries to reply to a topic or do a reply to a conversation, it gives this error. Despite of this error, the reply gets posted. It only displays after I refresh the page. I've tried disabling all the addons I've installed but that doesn't seem to solve the issue. What could I possibly try to solve this issue? I'm using XenForo 1.1.3 with XenAtendo, XenPorta, [bd] Tag Me and TaigaChat addons. There are few outdated templates.