Uncaught exception when closing a library that does not exists

[martinctl]

JabRef version

5.12 (latest release)

Operating system

macOS

Details on version and operating system

Sonoma 14.2.1

Checked with the latest development build (copy version output from About dialog)

• I made a backup of my libraries before testing the latest development version.
• I have tested the latest development version and the problem persists

Steps to reproduce the behaviour

1. Open JabRef
2. Do not create or open a library
3. Press cmd + w (ctrl + w) or File -> Close library

Appendix

Log File

ERROR: Uncaught exception occurred in Thread[#29,JavaFX Application Thread,5,system]: java.lang.NullPointerException: Cannot invoke "org.jabref.gui.LibraryTab.requestClose()" because "libraryTab" is null

[Siedlerchr]

Can you please try the latest development version? If I remember correctly this should be fixed already
You can use the https://builds.jabref.org/main/ arm64 version

[koppor]

Related #4795 (dplicate of #4665)

[martinctl]

I have tested the latest development version on mac and Windows 11 and it does not seems to be fixed

[martinctl]

Also I would like to be assigned to this issue if you think it's fine for a first time code contribution

[github-actions]

As a general advice for newcomers: check out Contributing for a start. Also, guidelines for setting up a local workspace is worth having a look at.

Feel free to ask here at GitHub, if you have any issue related questions. If you have questions about how to setup your workspace use JabRef's Gitter chat. Try to open a (draft) pull-request early on, so that people can see you are working on the issue and so that they can see the direction the pull request is heading towards. This way, you will likely receive valuable feedback.