I have this rather special case where there is a large number of labels in a single image (450). This is an instance segmentation problem, so this number is needed.

When trying to add labels in the multilabel segmentation tool, nothing happens. MITK is computing something for a while, but neither is the new label created, nor is anything added to the list of labels. In addition, 'the number of labels' counter is not increased.

To reproduce:

1. load image
2. load segmentation
3. right click on segmentation in data manager, select 'convert to segmentation'
4. open multilabel plugin, select data and segmentation
5. click 'Add new label', enter a label name + color
6. MITK computes for a while (~10s) (-> why does that take so long? Might also be worth investigating)
7. nothing happened. No new label was generated

Ubuntu 18.04 with 2021-11-09 MITK snapshot

Thank you :-)