After creating a new segmentation in the the MultiLabel Segmentation view, a pop up appears:

"Please load and select a patient image before starting some action."

though the patient image is already loaded and selected.

After confirmation of that dialog, all tools are disabled.

Click in the tools, click in the image, click in the tools -> tools get enabled

Select "Add" tool -> mouse pointer changes, a green contour can be drawn, but no segmentation is added or shown