Hello Monica
Are they working offline?
You can check it like this. Open SEP client click Help and support on rigth up side. Than click Trobuleshooting.
In the General information if Server is Offline you cannot them in SEP Mananger
You must to import profile with Sylinkdrop.exe
You can find this exe in Symantec Endpoint ProtectionCD2\Tools\NoSupport\SylinkDrop
First export you xml file in SEP Manger ( you can export it clients tab in SEP Manager )
than export it in user with sylinkdrop.exe
I hope this will help to you.
Thanks
Fatih.