I am using 7.5.4.2 at the moment and have noticed a problem when I make changes to certain CP items. For example, if I make any changes to the portal layout or make changes to an individual portal, and click submit, I get a white screen and it never returns to the CP. I have to manually go back to my site and re-enter the CP. This happens when I make any changes on things like Portal Setting, and Subscription changes, etc. It does not take me back to the CP.