When you say “DICOM segmentations” - what is the modality that shows up in the series list? Does it say “SEG” for the series you are trying to load in the DICOM browser? There are many ways how a segmentation could be saved in a DICOM file.
What happens when they don’t load?
Which extensions did you install?
If it is a DICOM Segmentation image object that you are trying to load, you will need to install “Quantitative Reporting” extension, and also all of the dependencies it will prompt you to install.