We've identified an issue with the 'rank rebuild' button; we discovered that in certain scenarios this function can sometimes cause performance issues on your community.
As a precaution, we've temporarily disabled the rank rebuild button.
We are looking into a permanent fix, and will re-enable the rank rebuild button as soon as we've resolved the problem.
Our apologies for any inconvenience caused.
In case you haven't used it in a while, here's a quick reminder about what this button does: pressing 'rank rebuild' updates all community member profiles to reflect any changes you've made to ranks (e.g. reordering, adding, editing and deleting ranks).