We are aware of a number of issues related to authentication when using ShareFile tools (Sync, Outlook Plugin, etc). In Sync, this has manifested with a prompt to re-authenticate. In Outlook Plugin, this can manifest by the plug-in appearing to be "grayed out".
The issue has the same root cause, and is being addressed via development and deployment of a hotfix to the ShareFile system, as soon as possible.
Until resolved, simply re-authenticating in Sync as prompted will allow it to connect.
For those receiving the Outlook Plug-in "grayed out", please follow the steps outlined in this support article: https://support.citrix.com/article/CTX223587
We sincerely apologize for any inconvenience this issue has caused. We will update this page once the hotfix has been successfully deployed.