Insider build 29648.1000 keeps failing to install

Hey everyone,

I'm stuck on this one. Every time I try to install the latest Insider build—29648.1000—it just fails. I tried installing it through Windows Update first, and when that didn't work, I downloaded the update manually and mounted it. Same result.

Current build is 29617, running Pro on a Lenovo IdeaPad. No error code that's been helpful so far.