If the session is left for long in ServicePoint the user is no longer able to login.
Steps:
(i) Leave the Xflow idle for long time i.e. couple of hours.
(ii) Now try to login and below error is seen:
"Unable to login. Contact Administrator"
(iii) Once services are recycled user can login.
Service Desk Manager 17.4 RU2.
This behavior is not seen with 17.4 RU3. Advised to apply RU3 if this issue is faced.