As I expected, your add-on.xml file hasn't been updated by the Updater, which is not normal and indicates that:
- Something external has prevented it to be updated, like an antivirus.
OR
- Your file has gone read-only for some reason
OR
- The simulator was running when doing the Live Update
Try to restart Windows, check if the add-on.xml hasn't been mistakenly gone read-only for some reason, and try again. If still doesn't change, REMOVE the whole folder that contains it:
Documents\Prepard3d v4 Addons\fsdreamteam Addon Manager
And reinstall GSX using the full installer. You will know the add-on.xml is correct, if it contains the line which add the new PBR Simobjects. Yours doesn't.