The managament service also offers the capability to audit changes in a separate log file. The auditing is mostly related to task definition changes.
There is a switch in the QMC, but it is greyed out. To enable QMS auditing, follow these steps: Check for when/by who a Publisher task was disa... | Qlik Community
If you use XML for your repository then locate your QVPR directory
You will find files like QVSCluster.xml there are many different files to represent different aspects of your QlikView setup. You'll need to find the correct file depending on which setting you want to see the changes to..
Most entries in these XML files have entries like
and from here you can see which AD user last made change and when that change was.
If you have automatic QVPR backups enabled then in this QVPR directory you will find another folder Backups which will in turn have a zip file for each back up made going back through time.
With this you might be able to find the changes made to your setting of interest and who made them.