Team Members Blocked from accessing the Project

Hi, I'm not sure if this is the place for this post but I can't find a more relevant one. Two team members who had registered with LEED online, found they were blocked when trying to access the project - first told their passwords were invalid and then blocked out completely (if it were just one of them I would suspect they forgot the correct password). So what I tried to do was to deactivate the team member then reinvite them, but the system won't let me reinvite a deactivated member. Has anyone come across this before? Any help or guidance would be appreciated.