Blank general tab with Java class error

Recently run into problem with Jabref5.2 and Jabref5.3 when going into the general tab.
Received a notification (first lines below)

  • java.lang.ClassCastException: class java.lang.String cannot be cast to class org.jabref.model.entry.BibEntry (java.lang.String is in module java.base of loader ‘bootstrap’; org.jabref.model.entry.BibEntry is in module org.jabref@5.2.60000 of loader ‘app’)

Then the general tab is empty.

Can somebody help please.

  1. Which Operating System (OS) and which Version of Jabref did you use exactly? You can find this information at Help>About JabRef
  2. Is there something special you did before entering general tab?
  3. Could you show a screenshot how it looks like?
  4. Does it happen with a clean installation of Jabref as well? (e.g. one of the portable versions: Download JabRef latest release)
  5. Are there any special entries in your library file that might be relevant? Did you try to edit or enter special characters into your library before entering general tab?

You might also want to check if resetting the preferences helps


Windows 10, tried with Jabref 5.3 and 5.2, windows installer, clean installation. I did remove them and install 4.3.1 and it works fine


Cannot send a screen copy unless I remove 4.3.1 to reinstall 5.2/5.3


No. I have been using Jabref for almost 20y now (great!!!) and usually, if I get a special character warning due to copy/pasting information, I directly correct it.

Hope it helps a bit

Thanks and best regards


  1. If you use the portable version of the 5.3 or even better, the portable version of the development version, then you don’t have to uninstall 4.3.1. You can have them both on your computer at the same time.

  2. Resetting the preferences did not help?

As far as i am aware, all versions of JabRef use the same configuration files, so maybe your 4.3.1 configuration is incompatible with the 5.3 version. Fefore you reset them in the 5.3 version, exporting your 4.3.1 configuration to a backup-file might be a good idea.

Using the 5.3 portable, I got the same erro, see attached picture.
Preferences reset did not help either.

Thanks for helping


Does the error emerge EVERYTIME you go into the general tap, or just sometimes?

Let’s get rid of all the user configured things that potentially could influence your system and try to get a clean install first. If the error then still happens to be, then it might be something outside of JabRef or indeed JabRef code.

Could you close all your libraries in the portable version and create a new library in which there is only a simple entry? Something like this:

  author = {new entry for test},

Does the error still emerge?

Also, here is the link to the development builds: index - powered by h5ai v0.29.0 (

I am using Windows 10 Jabref 5.3 as well and i can’t reproduce this error.

Maybe you could try to reset your preferences?

Etienne said: “Preferences reset did not help either.”