I managed to fix it. The problem was EnabledGraphics.exe (or similar) was stalling and causing the whole installer to stall, so when it did it’s job I just killed the process in task manager and it resumed. Says it didn’t install properly, but it’s been working fine so far even with Android debugging.
One thing to add to the transition guide:
FRepMovement now has additional flags for the precision of the replicated properties. By default, Rotation is replicated at 8-bits-per-value which is considerably less precision than before, and Velocity & Location are reduced to no-decimal precision instead of the old 2-decimal precision. Although this is great for most applications, if you are experience jittery rotation on client-controlled objects just change it to 16-bits per component and it’ll be back to how it was before. This is unfortunately undocumented in the release notes for some reason, and I’ve found a couple of changes to Slate/UMG that have broken a few other network-based activities. Shall report back when I know how to fix it.
It does also add a tiny bit of overhead to FRepMovement as well because those properties themselves are replicated - so be mindful of your bandwidth 