API Developer Portal login page does not show when clicking on Login button and throws a http 500 error page.
portal 5.x
This could occur when the portal internal certificates are expired .
By default they are valid for 3 years after installation . see the following techdocs to renew them.
https://knowledge.broadcom.com/external/article/199168/ca-developer-portal-renewing-pssg-dssg-a.html