For all my friends who have not yet started with August release of AX7, note down the following announcement.
Application Platform and Test Essentials models cannot be customized (over-layered) starting from the August 2016 release. Also, if you customize elements in the Application Foundation model, you will get warnings as this model is scheduled to be locked from customizations in the next Dynamics AX platform update.
I would add that avoid over-layering on Application Foundation, from now.
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