In eclipse,  I always get stuck on the "Generate Custom Entities" window when opening  Jpa Tools -> Generate Entities from Tables menu .

The configured connections is the Firebird one, and is already connected. There are no tables displayed and

the lower buttons (Back Next and Finish) are disabled.

That is using a Jpa project, with EclipseLink 2.5.x, Generic 2.1 and Hibernate .

Eclipse version is Version: 2019-03 (4.11.0)  Build id: 20190314-1200

Firebird is LI-V2.5.8.27089 running local

Using MySQL just works.