Unable to bring up Application server with error Could not sign on to database XX with user XX

Unable to bring up Application server with error  GenMessageBox(0, 0, M): Database

Signon: Could not sign on to database XX with user XX.

When this message is printed in log file. Follow these simple steps

1. Validate your user login through Application designer.

2. Validate your connect id login through sql plus or data mover.

3. If you have DB2 database. Make sure you have catalog entry for target database and System DSN populating it. ODBC data source administrator 64-bit -> System DSN

4. None of above works then setup people tools trace.