The below error message appears when you try to enable an existing pagelet for a new Role or Permission List.
Error executing pagelet.
Detailed error description:
The current user has insufficient privileges to complete this operation.
This happens, when you are modifying an existing pagelet that is generated using Pagelet Wizard in Portal Interaction hub (aka Enterprise Portal 9.1) and added a new permission List or Role using Structure and Content.
The issue is Pagelet Wizard has its own security that is stored in the below table.
select * from PS_PTPPB_SECURITY where ptppb_pagelet_id = 'YOUR_PAGELET_ID';
You can add the new permission List, by Going thru Pagelet Wizard steps again.
Menu Navigation : Portal Administration -> Pagelet -> Pagelet Wizard
Once you add the permission List or Role using the Pagelet wizard, this error will go away.
I encountered this issue for a Pagelet based on Navigation Collection. This is not properly documented and is difficult to troubleshoot.