Oracle Initialization Error

Oracle Initialization Error while logging to App Designer.
Check the TNS entries are correct or not.
Check the ORACLE_HOME/TNS_ADMIN and PATH variable is set to correct values or not.

Make changes if needed to these variables and test the login again.
This should resolve the issue.

App Designer Login Issues

Problem: Not able to change peopletools objects from App designer.
Resolution: Need to add "PeopleSoft Administrator" role to the userid.

Problem: Invalid username/password while logging to App designer.
Resolution: check the TNS entries placed in Orahome (Place where oracle software is installed) /network/admin folder. See that the SID , port and domain are correct.

Problem; Want to change the default PS logo.
Resolution: One quick way is to create an image object of same dimension (usually 145 x 41) , and upload through App designer.