Markings lost on upgrade

Hi!

I just upgraded to version 4.0 (from 3.8) and now all my previously marked entries don’t show up any more. When I mark an entry manually, everything works as expected. Where have my markings gone? Is there a way that I can recover them?

Stephan.

JabRef 4.0
Windows 7 6.1 x86
Java 1.8.0_151