Hi Jason,
Thanks for the response. I tried using the WD component and deleting the personalization of that user. But it didn't work. I was able to trace the issue finally.
The user had checked a field "Include completed shopping cart" which is seen on clicking the button
"Show quick criteria maintainence". The issue was with a old shopping cart with line item description
in chineese language. In my screenshot you can see the highlighted description, this description was
maintained in chineese language.
The user checked the check box and dragged the scrollbar in the POWL to see old SC, when that SC
came into the view of POWL because of dragging. It gave the error.
To Confirm, I tried to open the SC from Application Monitor and did the same thing , dragged the line item, and it gave me the same error.
Not sure, if Portal 7.4 has any restriction or issue in displaying the language.