The box in the "External Changes Resolver" should be scrollable

1. Create a new library with a few groups and assign some entries to them
2. Outside of JabRef, open the bib file in a text editor, scroll down to the end of JabRef and modify the group structure, e.g., change the group name or add new group by copy and paste
3. Wait for the dialog "This library has been modified by another program"
4. Click on Review Changes
5. See the metadata like in the screenshot