FortiToken Mobile "must activate your token by" date is expired

We have one user who is not able to VPN. His mobile ForiToken app tells him his account is expired. When I re-send him his Activation code via email from within FortiGate, this is what his email says:

"You must activate your token by:  Thu Apr  5 09:54:31 2018 (GMT-5:00) Eastern Time (US & Canada), after which you will need to contact your system administrator to  re-enable your activation."

I am not sure how to re-set or refresh this date.  It seems to be an issue only for this user.