After applying AEM 6.3 SP1 + CFP1 or later patch on systems where "SSL is terminated at the load balancer"  (or web server), users are no longer able to log into AEM.
 SSL being terminated at the load balancer or dispatcher means that AEM is accessed via http:// but when accessing via load balancer you use https://.
AEM 6.3 or later version
After installing AEM 6.3 SP1 + CFP1 or a later service pack / CFP, make the following configuration changes:
This setting works only for the X-Forwarded-Proto: https header. Make sure that your load balancer or web server is sending this to AEM when users are connecting via https.
Users should be able to log in via the load balancer / dispatcher after changing these settings.