ax_message_pkg is invalid
We are upgrading from Apps 11.5.10 to Release 12.1.3. After the upgrade we noticed that several custom objects were invalid, which was anticipated. Research into these led to AX_MESSAGE_PKG being invalid due to dependent core packages such as AX_CONCURRENT_PKG, AX_ENVIRONMENT_PKG, AX_EXCEPTIONS_PKG etc being invalid. What might have caused these core objects to become invalid and where do you start to fixing these? Any direction to fixing this will be greatly appreciated.