This build is definitely from a different branch .. 15048 edge was really bad shape but this build edge is sooo quick and responsive... overall this build feels solid.
Glad to say that my Windows Update UUP upgrade to 15055 from 15048 went perfectly, first time... Seemed to take a bit less time, too. Nice! Haven't needed an iso for the last two UUP-delivered builds. Looks like they are approaching final for release.
The reason you are getting that error is because you didn't copy all the files needed to build your image from the UUP folder, most especially, from the directory 1033.
Seems like the blank screen is sorted now but for how long unsure .. Also this new Window Boot seems to reset everything in the Bios with Clover Boot when you boot into Windows via Clover .. They still need to sort out these auto update drivers via Windows Update because it's causing problem with old drivers they keep trying to install over the news drivers from the user to be honest .. Also doesn't help whatever way you try to block it the OS / Windows Update overrides it truth of the matter .. Oh before I forget did anybody noticed when installing this build over 15048 a blue screen at 30 percent .. it also stated that it would do a recovery but doesn't and still install this build ..
I for myself, let WU update my drivers as it wishes but, of course, on my test rigs, in case something goes wrong I report, do you know why? I'm an Insider