Image lightbox stopped appearing on beta 8 update

[jomaxro (Joshua Rosenfeld)]

@fearlessfrog

Is there something in the beta6 to beta8 that recooks all posts or something?

Yep, see Discourse 2.2.0.beta8 Release Notes

@jomaxro

Important Note: Expect high CPU usage for a few hours after this upgrade due to image re-optimization. Sites with large numbers of images may see high CPU usage for a longer period of time.