R12 Login page is not opening, a blank page is being displayed.

Below is the error in the oacore log

javax.servlet.ServletException: java.lang.RuntimeException: Guest user/pwd does not exist or match: GUEST/ORACLE


Running the below query, confirmed that GUEST user and password was not in sync

select fnd_web_sec.validate_password('GUEST','ORACLE') from dual;

FND_WEB_SEC.VALIDATE_PASSWORD('GUEST','ORACLE')
--------------------------------------------------------------------------------
N


Solution:
1. Shutdown the EBS services.
2. Use the below API to reset the GUEST user password:

java oracle.apps.fnd.security.AdminAppServer APPS/<APPS Password> UPDATE DBC=<Full path of EBS DBC File> GUEST_USER_PWD=GUEST/<Guest User Password>  DB_HOST= <Host_Name> DB_PORT=<PortNumber>
DB_NAME=<SID>

3. Run autoconfig on DB Node and then application node.

4. Execute the below sql again:

select fnd_web_sec.validate_password('GUEST','ORACLE') from dual;

Check whether query output is showing Y.
If no,  Please check whether the below error is seen on autoconfig log:

Unable to update GUEST_USER_PWD in database to GUEST/ORACLE - Password was not changed, this point to the DB parameter JAVA_JIT_ENABLED which is set as TRUE.

5. On 11g DB you need to have the below settings for EBS specifically, run the below sql

alter system set JAVA_JIT_ENABLED= FALSE scope = both;

6. Follow the steps 2 and 3 again.

7. Run the below command:

perl $FND_TOP/patch/115/bin/ojspCompile.pl --compile --flush -p 2

7. Check whether the compile completed successfully.

8. Restart the application services.