I’m using EndNote X8 on Mac OS SIerra (version 10.12.6). When I want to sync my online library on desktop, I’m going to Preferences, then Sync and, after that, Enable Sync. I write my e-mail address and my password. A window opens for a registration. I write my first and last names, I click on “agree”, but I have this error message : “EndNote registration could not be completed at this time. Please contact technical support.” and I can’t sync. What can I do ?