Also, and this is totally anecdotal, but both times my sites broke (two different sites) I’m 99% certain they broke after I had renamed a pre-existing repeater. I haven’t experimented to see if this is certain.
So I don’t know why it is breaking from a code perspective, just that I’ve stumbled across a fix for my particular situation.
I hope it works for you!
Remember, make a backup! 🙂