[UE4.22]Stuck[crashed?] on making new Blueprint Class with macOS Mojave & Xcode10

Hi UE team,
i met a desperate problem when start learning UE4.
that is every time when i try to create a new Blueprint Class, my Editor got stuck and can’t come back.

this is what i did:
1.i simply download this project for learning.

2.create a New C++ Class in type of Actor. switch to the Xcode automatically.

3.switch back from Xcode to the Editor,select Blueprints Folder under Content, right-click the folder, New a Blueprint Class.

everything stuck here. the Blueprint Class creating window didn’t shown up,
and Editor got froze and no react to my operation. only the mouse mark turned into a rotating vortex which means something is loading,

but i have wait it over 3 hrs and nothing changed.
also i have tried 4.20 and 4.21version of Editor on 2 single Macs(one is iMac2015, another is MacPro2015, both in Mojave with Xcode10, and mono 5.20), they met the same problem.

so i guess the problem is caused by engine or Xcode. have you guys got any reports about this?

Are you able to reproduce it in a fresh project? If so, you should submit a bug report here: Report a Bug - Unreal Engine

I’m having the same problem. I have 4.22.3 and MacbookPro with Mojave.
I’m trying to follow this tutorial: , and when I try to make the 4th Blueprint class it freezes (rainbow of death cursor) until I forcekill it, and no matter how many fresh projects I make, it always gets stuck at the same step. (Different from the OP, I do have xcode installed, but for reproducing, it’s not opened at all). I’m trying to downgrade now to see if the problem is with 4.22.3