Unable to install Extensions

I am experiencing problems downloading two extensions with a school district laptop: MuseScore General HQ and MuseScore Drumline. When prompting the software to install either extension, I get this message in a pop-up notification:
"Cannot import extension: storage //rljunk/stafffiles/pmillican/Documents/MuseScore3/Extensions is full"

When I check the extensions sub-folder in my Musescore 3 folder, it is entirely empty. So, might the computer be trying to save the extension files to a folder that is prohibiting the software from doing so? Please, share your thoughts. Thank you.