at org.basex.gui.view.project.ProjectFiles.add(ProjectFiles.java:167)
at org.basex.gui.view.project.ProjectFiles.add(ProjectFiles.java:173)
at org.basex.gui.view.project.ProjectFiles.add(ProjectFiles.java:173)
at org.basex.gui.view.project.ProjectFiles.add(ProjectFiles.java:173)

Looks like a endless loop that is caused by parsing the files in your project directory. Do you possibly have any symbolic links?

Can you reproduce the problem with a completely fresh BaseX zip archive?