Thank you for posting in the Final Fantasy XIV Technical Support Forums,

We apologize for any inconvenience that has occurred when playing FFXIV. The unable to complete version check error means that there is an issue with the connection. Please provide the following information:

-Wired or WIFI connection
-Other programs being used when running FFXIV
-When disconnect occurs/How often
-Everything you have tried to resolve the issue

Hope you see you online!