Jabref freezes and is very slow

I updated my Mac to High Sierra, and upgraded Jabref to 4.0.
I have java version "1.8.0_144"
Java™ SE Runtime Environment (build 1.8.0_144-b01)
Java HotSpot™ 64-Bit Server VM (build 25.144-b01, mixed mode)

JabRef freezes if I try to create a new Bibtex entry. Following this github thread https://github.com/JabRef/jabref/issues/2963, I tried to run the current master. The entry editor did open (very slowly), but each step is so slow that it’s almost as bad as if it had frozen.
In the process, I get a warning that says
[AWT-EventQueue-0] WARN org.jabref.logic.l10n.Localization - Warning: could not get message translation for “ID-based_entry_generator” for locale en

This seems to refer to an known problem for Mac OS X High Sierra which is already be added to our FAQs - more information can also be found here at GitHub:

The solution is also discussed there:

I did some research. This article suggests explicitely adding the hostname to /etc/hosts - and the window opens after a few seconds. I did just a short test but it looks promising. Will close this bug if I can confirm this. Funny that it was no issue for 3.8.2.