EBS 12.2 -- Can not login after upgrade -- Login failed. Please verify your login information or contact the system administrator.

The issue appears in upgrade customers, and the login page just fails with the following;

Login failed. Please verify your login information or contact the system administrator.

If you have done an EBS 12.2 (for instance EBS 12.2.10, 12.2.11) upgrade and can't login to EBS.. (using SYSADMIN or any other user);

If you face a situation where you end up with Login Failed message when you enter the credenatials on Login page and click submit;

If you tried changing/resetting the passwords using FNDCPASS-like utilities, but the issue still persists;

If FND_WEB_SEC.VALIDATE_LOGIN returns Y for your users,

If there are no significant errors  in oacore_server1 out, diag or log files +  Apache/OHS diag files, 

then ->

run the EBS upgrade Analyzer! Again we have an analyzer to use ! : ) When saying "we" , I don't mean "me", actually Oracle has one :)

E-Business Suite Upgrade Analyzer - 12.X to 12.2.X ( Doc ID 2634237.1 )

So, we run the analyzer and check its output.. ( we don't be lazy for running these analyzers, they actually save us time!)

Most probably, the analyzer will tell you that the following patch is missing in your system;

Patch 32357755: SYSADMIN (WHEN PASSWORD REUSE IS ON) PASSWORD CHANGE DOES NOT WORK AFTER UPGRADE FROM R12.1.3 TO R12.2.

Just apply the patch and the issue will dissapear..

Note that, as you may have already noticed the definition of this patch doesn't directly map to our issue, but the conditions that I gave above actually redirects us to this patch ( even without checking the analyzer output).. This may be the insight of this blog post. When it comes to Oracle patching and documentation and especially the patch definitions, I 'm the voice of the skeptics:) 

So that's why I've put that long "if" part in the beginning and only then, that precise "then" part is given :)