Internal Server Error while submitting expenses

Hi All,

One of my business user is facing issue while submitting his expense report. He is getting "Internal Server Error"  after clicking on Submit. Only couple of users are facing this issue rest all are able to claim their expenses.

EBS : 12.1.3 and 11.2.0.3

In backend i can see this SQL going in loop forever however i've checked his Supervisor ID and its correctly updated. There are no loops in his supervisor hierarchy.

This is the first time user is submitting his expense.

SELECT SUPERVISOR_ID

FROM PER_ALL_ASSIGNMENTS_F

WHERE PER_ALL_ASSIGNMENTS_F.PERSON_ID = :B1 AND PER_ALL_ASSIGNMENTS_F.PRIMARY_FLAG = 'Y' AND PER_ALL_ASSIGNMENTS_F.ASSIGNMENT_TYPE IN ('E','C') AND PER_ALL_ASSIGNMENTS_F.ASSIGNMENT_STATUS_TYPE_ID NOT IN