entries missing...

I am migrating from Jabref 2.10b2, running on Ubuntu 14.04 LTS (installed, not Jar)

t0 Jabref 3.8.2, running on Ubuntu 18.04 Bionic (installed too).

I have installed Java 8 from Oracle

I experience the following problem:

When I open my “library” file, I have 3355 entires on my old setup.

On the new setup, I only see 748

When I open the Library file in the new setup, I get the following error message:

  1. Error occurred when parsing entry: ‘Error in line 9268 or above: Empty text token.
    This could be caused by a missing comma between two fields.’. Skipped entry.
  2. Error occurred when parsing entry: ‘Error in line 11101 or above: Empty text token.
    This could be caused by a missing comma between two fields.’. Skipped entry.
  3. Error occurred when parsing entry: ‘Error in line 56423: EOF in mid-string’. Skipped entry.

QUESTION:
What do I do to get all my 3,355 entries to re-appear in my new setup?

This migration issue was encountered before. See https://github.com/JabRef/jabref/issues/2799 .
You will have to open your bib file with a text editor, and manually edit the file. The error messages will help you locate the line that cause trouble. Hopefully, it will not take too long.