Drag & Drop from Project View into (JavaFX) Editor

I'm trying to enable drag & drop for files from the project view to an editor window. More specifically to a JavaFX TableView.
Even though drag detection seems to work correctly (cursor changes), when I drop it, I don't get notified and I get this exception:

> java.awt.datatransfer.UnsupportedFlavorException: Unicode String
> 	at org.openide.util.datatransfer.ExTransferable.getTransferData(ExTransferable.java:152)
> 	at sun.awt.dnd.SunDropTargetContextPeer.getTransferData(SunDropTargetContextPeer.java:241)
> ....


My Code:

Code:

        componentTable.setOnDragOver((event) -> {
            if (event.getGestureSource() != componentTable
                    && event.getDragboard().hasFiles()) {
                event.acceptTransferModes(TransferMode.LINK);
            }

            event.consume();
        });
        componentTable.setOnDragEntered((event) -> {
            if (event.getGestureSource() != componentTable
                    && event.getDragboard().hasFiles()) {
                //todo
            }

            event.consume();
        });
        componentTable.setOnDragExited((event) -> {
            //todo
            event.consume();
        });
        componentTable.setOnDragDropped((event) -> {
            Dragboard db = event.getDragboard();
            boolean success = false;
            if (db.hasFiles()) {
                //todo
                success = true;
            }
            event.setDropCompleted(success);

            event.consume();
        });