ProjectLibre not working properly

From the repository I just installed ProjectLibre: It looks fine but is not working properly. Steps to reproduce:

  • Start ProjectLibre and create a new project.
  • In the spreadsheet, column “Name” enter two Tasks named T1 and T2 just underneath each other.
  • Mark the line with T2 by clicking the very first column.
  • In the register on top switch to “Task”.
  • Almost centered, there are Options “Insert”, “Delete”, “Indent” and “Outdent”. Click one option and nothing happens (here).
$ java --version
openjdk 16.0.2 2021-07-20
OpenJDK Runtime Environment (build 16.0.2+7)
OpenJDK 64-Bit Server VM (build 16.0.2+7, mixed mode)

Please read this:

then file a bug upstream…