java.lang.RuntimeException: Failed to open project for exercise osa01-Osa01_39.NegatiivistenLukujenMaara
[catch] at fi.helsinki.cs.tmc.actions.DownloadExercisesAction$1.bgTaskReady(DownloadExercisesAction.java:82)
	at fi.helsinki.cs.tmc.actions.DownloadExercisesAction$1.bgTaskReady(DownloadExercisesAction.java:69)
	at fi.helsinki.cs.tmc.utilities.BgTask.call(BgTask.java:173)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1443)
	at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:68)
	at org.openide.util.lookup.Lookups.executeWith(Lookups.java:303)
	at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2058)