Knowledge Base: if GanttProject 3.+ won't launch after installing a new update

We have a few reports about the issue with launching GP 3.0 where it starts and hangs at the splash image (other symptoms are also possible)

Possible reasons and configurations where they are applicable to are listed below.

1. Missing update

This applies to GanttProject 3.0.+ on all operating systems. This is not applicable to GanttProject 3.1.+

GanttProject 3.0.+ may fail to launch because of a missing update which was skipped. Unfortunately, due to a bug in the update system, the update which was skipped won’t be install afterwards, even if subsequent updates depend on it.

Updates location on disk

The workaround which fixes such issues is to remove all installed updates from disk. Normally the updates sit in the folder ~/.ganttproject.d/updates in the user’s home folder.

Removing the updates

On macOS and Linux, one can remove the updates by running the following command in Terminal:

rm -rf ~/.ganttproject.d/updates

On Windows one can find and remove .ganttproject.d. folder in the user’s home folder using their favorite file manager. The user home folder on the modern Windows systems is normally C:\Users\<your user name here>.
Please pay attention to the leading dot in the folder name. Some file managers may hide such folders.

What’s next

After removing the updates, launch GP 3.0 and let it install all updates. This should fix the issue.

2. Missing JavaFX libraries

This applies to GanttProject 3.1.3100 running on Linux systems and installed from DEB package.

GanttProject may fail to launch after installing update 3102 if there are no JavaFX libraries in the Java Runtime which is used for running GanttProject. Those libraries are shipped with DEB package, however, update 3102 replaces the plugin with these libraries with a newer version where JavaFX libraries are missing.

Windows and macOS distributions are not affected because they are bundled with Java Runtime which includes JavaFX. ZIP distribution is not affected because it never included JavaFX libs, so if it was working before installing update 3102, it should continue working after installing it.

Possible solutions

Any of the following will solve the issue:

  1. Use Java Runtime with JavaFX libraries, e.g. BellSoft Liberica Full JRE or Azul Zulu.

  2. Copy JavaFX libraries from the base installation to the updates. The following command shall do the trick, provided that all installation paths are the default ones:

    cp /usr/share/ganttproject/plugins/base/* ~/.ganttproject.d/updates/update-3102/


It did happen, and solution works.
Thanks Dimitri.

Happened to me too.
Maybe related: After every update installation it asks for reboot and then hangs at the splash screen.
Closing the application / splash screen and then restarting starts GP correctly with the correctly installed update.

then hangs at the splash screen

That’s strange. In my tests it either restarts successfully or won’t restart at all (seems to be an issue in DEB distro). What OS are you using?

Win 10 Pro.
I see this behavior since the auto update is available. It never correctly restarted after an update.

1 Like

Happened to me on Ubuntu 20.04 even after the command, I also had to de-activate automatic updates and launch all updates from the settings tab.
Thanks for the workaround anyway !

I have the same behavior on GP 3.1 after installing it and trying to update it from 3.1.3100 to 3.1.3102 on my setup under Ubuntu 20.04. Even deleting the update folder, I can’t even update through the config tab anymore. If I do, I can no longer restart GP, the task is indeed present on my system monitor, but nothing on display.
I must specify that I use for Java, the OpenJDK 11 (latest version available), is this a possible cause for this bug?

Update-3102 broke running Ganttproject on Linux.
The solution works, but:
1) sequential installation of updates does not work
2) the previous update (3101) was installed (not currently).

If you use your own Java Runtime, you have to use one with JavaFX libraries. It is either Bellsoft Liberica or Azul Zulu.

I have updated the article, see “Missing Java FX libraries” section.

Debian package has been updated:

It is GP 3.1.3102 with JavaFX libraries included.