RE: I do not have the Update now option. What is the latest version of Connections?
Are you the site admin? If not, you should contact that person and have them do the upgrade as only the site admin has the ability to update plugins in the WP admin.
RE: Is this error unknown to other users?
The version of Connections you have installed is over three years old now. There have been dozens of updates to Connections since. I suspect this warning message was dealt with long ago in one of those past updates.
Hope this helps! Let me know.
ps. It is considered a best practice to log, not display PHP messages on the screen on live public sites as that can reveal private information. You should see this tutorial on how to suppress these developer messages.