Security - all users report showing roles held in the system

Summary:

I am looking for a report or some advice about how to build a report which shows all users that have a security role in Cloud. My aim is to be able to audit/check that users hold the appropriate security roles in the system. I complete a recertification process twice a year but ad-hoc checks on a monthly basis.

Content (required):

We previously have been using a report built from the Security - roles and privileges table but it has suddenly stopped working. I have found that the out of the box 'user role membership' report isn't useable in its current format since you get duplicate rows and it has leavers on it. I get 307,000 rows. The user and role access and audit report has too much information on it.