Select Series 4 - Activating Against a Select Server Error

I've recently become my Department's Bentley administrator and have been running into some issues I'm not sure how to address. Most of the department Users are using Select Series 10, but I have one User in particular that still has Select Series 4. After doing a bit of research, I saw that the major difference between SS4 and SS10 is the implementation of the new Subscription Entitlement Service licensing method and the use of the Bentley Connection Client. From what I read, SS4 doesn't use the Bentley Connection Client, which may be why the User is having so many issues. 

Previously, the SS4 User received an error regarding their license being expired and that their Microstation would only work in 15 minute increments.  Closing out of the file they were trying to open, and then reopening it, seemed to fix the issue for the time being. (Classic IT technique, haha)

This morning, the SS4 User received an error regarding activating against a select server but I'm not sure what it's referring to. (I've attached a snip of the error below) I attempted to browse the forums for an answer, but didn't find one. Could someone help explain what his software is trying to do/asking? If there is a solution, what is it? Could this error be avoided by upgrading his software to SS10?

Thank you in advance!