Expense user getting "ORA-01427: single-row subquery return more than one row"

We have issue when user clicks on expenses icon get the below error message. User is not able to perform any action in Expenses module

User can navigate to other modules succesfully without issue .Delegate is blank page for this user

We checked

-No latest HR changes

-User had succesfully submitted expenses previously and recently found this issue

-User is not using any other functions in the application to cause this error