Problem Running for Debug

Hello,

There’s seems to be problem with the UE4 Editor Initialization Phase.

I’ve downloaded VS 2017 CE, v15.9.4, and the UE4 source code v4.21
along with all of its batch-file requested stuff.

It compiled just fine, but when I pressed {F5} in order to debug it,
it returned the following 2 screens :

1.) Initializing… which stopped at 45% :

Photo # 1 shows both the editor’s loading percentage and an Output Window message,
both surrounded by a red frame, when everything is pending…

2.) Some sort of “Freeze” :

Photo # 2 shows both the editor’s loading percentage and an EXIT Output Window message,
both surrounded by a red frame, along with the previous message surrounded in blue,
when the loading sequence seems to have frozen.

Would anyone know why this is happening – thus be able to tell me how to fix it ?
Thanks much in advance
GB