UE can't launch

I’ve tried with the versions 4.18, 4.19, 4.20 and 4.21, and also uninstalling and reinstalling both and UE version and the whole Epic Games launcher, and the result is always the same. It tries to launch UE, hides the window, thinks for a moment, and nothing visible has happened, as shown here:


I’ve found similar questions posted and solved, but their proposed solutions haven’t worked in my machine.

I’m currently running MacOS Sierra, where UE is running properly in other machines.
I can also not restore my computer to factory settings (since I need my public key certificate at least until June, I’m now in Korea and I would only be able to renew it going back to Spain, which really can’t before June).

What could I do in order to be able to open UE again?
Thank you so much for helping!