MyPhone cautioned their consumers of potential device crashes brought about by the new FB app update via their Tech Support page.
According to MyPhone units with 512MB RAM are no longer compatible with Facebook due to the new update and will cause your device to display “Android is optimizing” during startup. As of writing, there is yet to be a solution to the problem. Users are instead, advised to use the Facebook Lite app as an alternative for the time being.
We will update this article once a solution comes to light.