Issue with Enrolling Students via Fluid Structure - "Enrollment Override Record Not Found" Error

I'm encountering an issue while trying to enroll students through the Manage Classes tile in PeopleSoft Fluid Structure. When I attempt to enroll a student, I get the following error:

"Not processed due to system error. The enrollment override record was not found for the enroll access ID. No transaction requests were processed."

I've ensured that the student has valid enrollment records, but I'm unsure why this error is occurring. Has anyone experienced this issue before? Any insights on what might be causing it or how to resolve it?

Thanks in advance for your help!