Edit: this solved my problem:
https://answers.unrealengine.com/questions/915798/editor-crashes-at-45-meshutilities.html?childToView=917052#answer-917052
94, you still around? Also having this issue. Crashes at 45%. Something to do with MeshUtilities. Deleting those folders didn’t work for me.
Assertion failed: Module [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Private\Modules\ModuleManager.cpp] [Line: 373] MeshUtilities