EDIT: Okay, seems I didn't quite look thoroughly enough before asking this, apparently an add-on for "Ninja Download Manager" was causing problems. Please disregard this question, I apologize for wasting anyone's time. For some reason, a lot of my downloads end up with strange names and without a file extension. For example: If I try to save a PDF file from my university with the following link. https://mylo.X.edu.au/d2l/le/content/235142/topics/files/download/2789744/DirectFileTopicDownload the file gets saved as "DirectFileTopicDownload" (that is part of the link, it has not been replaced or changed like the X has). Alternatively, when I try to download executable files, often I end up with a string of numbers and letters which Im fairly certain is related to the files in question, though I can't tell how ( a quick google search of the string tends to lead to a related site etc.). FOr example, when trying to download a companion app for the firefox extention VideoDownloadHelper, i get the extension-less file "c036135a-7faa-11e8-87ad-cc9be00dd6d8" I would appreciate any help in this matter, bearing in mind I have reinstalled Firefox once already.