The upcoming macOS Mojave update enhances the functionality of the "System Integrity Protection" feature. This will prevent Origin In-Game from functioning.
You can disable System Integrity Protection in macOS to continue using Origin In-Game:
Follow the same steps to re-enable System Integrity Protection, but instead type "csrutil enable" in the Terminal.
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Try these steps first to clear up any problems you may have when connecting to an EA game.
Reset, update, or link your account information.