I've used JabRef for quite a few versions. I now have a problem with v2.10 that I do not have with v2.9.2. The attached shows the output of processing a file sumJ.bib in a folder containing JabRef.jar and jabref.xml. I make a hard link from JabRef-X.XX.jar to JabRef.jar and run
java -jar JabRef.jar -n -i sumJ.bib -o J.sumJ.bib
In the attached zip file, the two log files, log.2.10 log.2.9.2, are the result of using
ln JabRef-2.10.jar JabRef.jar and
ln JabRef-2.9.2.jar JabRef.jar, resp. Note that v2.10 fails without output. The desired output is given in J.sum.bib as obtained using v2.9.2.
I realize that there is some problem reported whenever I use JabRef, as seen in log.2.9.2. However, the output is just fine for my purposes in preparing technical papers.
I run JabRef under Cygwin on my Thinkpad Carbon Touch X1 with Windows 8.1 Pro x64 and Java-7.51 x32. (JabRef-2.10 also fails with Java-7.51 x64.) Java is in the standard installations under Program Files (x32, etc.).