ERROR: "Internal error. The Source Qualifier [] contains an unbound field" while running a workflow in PowerCenter

Problem Description
While running a workflow in the PowerCenter, the following error message is displayed:

Internal error. The Source Qualifier [] contains an unbound field []. Contact Informatica Global Customer Support.

Cause
This issue occurs when there are one or more unconnected ports between the Source and Source Qualifier.

Solution
The error encountered is not a product bug. It can be overcome by good mapping design and usage.

SQL to find Monday and Friday of the week of a given date

select next_day (sysdate-7,'FRIDAY') Last_Friday, next_day (sysdate-7, 'MONDAY') Last_Monday from dual;