Error while restricting standard memo line lov on AR Transaction form using custom.pll

Hello,

We have a requirement to restrict standard memo line lov on the AR Transaction Form (ARXTWMAI).

We tried to achieve this using Forms Personalization, but it didn't let us to create a record group with a SQL query more than 4000 characters in length.

Therefore, we tried using CUSTOM.pll but ended with the below error message when clicked on description field.

FRM-41076: Error populating group

and when clicked on list on values, it displays 'FRM-40502: ORACLE Error: Unable to read list of Values'

Kindly suggest to resolve the issue.

Written the below block of code in the 'event' procedure to achieve the requirement.