University of Maryland College Park. I'm a Teaching Assistant. Can't view previews in Speedgrader. Says "Service is currently unavailable. Try again later". Similar issue with some other files, i.e. syllabus. Seems to be an issue displaying previews overall. I've tried using Microsoft Edge, but same issue. 

UPDATE: Previews work now for me, but they load veeery slowly. I think it's a local server issue because my professor was able to access the previews from off campus.