Not sure if this is necro but I had the exact same problem. It was crashing at 96% - I deleted 2 files.
C:\Users\USERNAME\AppData\Local\UnrealEngine\4.8\Intermediate - There should be a filed in here called CachedAssetRegistry, delete it.
Now go to your project files and delete it again in your \Unreal Projects\MyProject\Intermediate
Worked like a charm for me, this was caused by a UE4 crash while building lighting or at least that’s what caused it for me. (Already sent the crash info for that)