There are 3 reasons why a clash would not show on a Component Clash Analysis Report
1 The Award has not been attached to a Course.
You can check this by right clicking on the Award and select Properties, is the correct course showing in the Course field? If not go into Course Manager, select the Course and add the Award in section 3 Exams
2 The student is already Seated
Check in Seating Organiser
3.The student is a member of both the AS and A2 courses
This is usually only an issue with AQA exams where you have split the Basedata. If the student is on both the AS and A2 course and has an entry for an element which is under both the awards, this creates multiple pathways between components and the clash will not be picked up. To resolve the issue Right Click on the Element you wish to removed and select Removed Element From Award.