Could not find Java SE Runtime Environment when starting portable snapshot

I downloaded the latest snapshot for linux portable, extracted the tar.gz and run ./JabRef/bin/JabRef.
But all I get is
Error: could not find
Error: Could not find Java SE Runtime Environment.

There should be a JRE shipped with JabRef right? And i can find at ./JabRef/lib/runtime/lib/

Do I need to do any more setting up?

Just as a note here, this problem seems to be solved, or at least we found out what the problem seems to be:

Just as a workaround: Do not store the jabref folder in a folder called bin.