Additionally, this just happened to me now. I started a new thread with the person on the desktop site since the mobile site has the thread locked. I was able to send the thread, but not even the new thread with this member will open on the desktop site. I HAVE to use the mobile version of the site to communicate with this member now.

Elizabeth I will need admin access details for the website and Cpanel access details in PM please. I will take a look at the issue. 

Thanks ross. I actually solved this myself yesterday and forgot I had posted this here. I ended up having to remove the plug-in (not simply deactivate it, but uninstall it completely). When I re-installed the latest plug in, it looked different (I have buttons now where there were none which is cool). We ran some tests and now it seems to have cleared up its previous issue and works between the built-in mobile site and desktop site. So here's hoping it stays all nice and pretty :3

Elizabeth, can you please specify, which plugin you have removed? messages?

Yes ross, it was messages I uninstalled and reinstalled. I am wondering if an update I did on another pluging caused it to have a problem. ??? But yes, after uninstalling and reinstalling, it worked fine.

Alright, I'm going to mark this post as solved for now.