2 users having issues uploading Excel spreadsheets in xls xlsx and csv formats.
They get “file type not allowed” however they CAN upload all other file types incl doc docx and pdf.
Tried it on their local machine (laptop) and on a virtual desktop, have the same issue on both devices.
Are they both in the same user group? A quick check it is whether or not the user group(s) they’re in have any customised preferences, especially “Allowed File Extensions to Upload”.