While using Xlink 7.3.1.7 Whenever I could get connected, if I allowed the Messenger Mode arena to run, Xlink Kai would stop working regardless of which server I was able to connect to.
So what I do is start the engine, login as usual, but NOT expand the UI to the messenger mode, instead click on the world ICON next to the mag glass, this way KAI would run without too much of a problem.
I still could not access the messenger mode without failure, but at least I could play some games.