I have seen a strange behavior of ObjectDB Explorer: it shows @Id as being Long, not Integer as it's normally declared in the java class. This happens now with all entities in all 3 databases used for one project.
If I open one of the entities in the explorer, then I click on it's id (in the sample on parts of the Embedded id) as if I would want to edit, then I press enter and ObjectDB Explorer shows the field type as Integer, as it should normally be.
I have attached just a small sample to see.
2.5.3 and 2.5.4_05 have been tried, and both have this error.