# login to Admin Console
# go to {nav Website & Content > Structure & Data} section
# click on `Sections` tab
# open any category for editing
# click on icon under `Description` field to open CKEditor
# click on `Insert/Edit Document` icon on toolbar
# click on `Browse Server` icon
# confirm, that it's possible to upload file with any of these extensions: `docx`,`dotx`,`docm`,`dotm`,`xlsx`,`xltx`,`xlsm`,`xltm`,`xlam`,`xlsb`,`pptx`,`potx`,`ppsx`,`ppam`,`pptm`,`potm`,`ppsm`