This issue can be tested in Android or iOS (it doesn't require to be tested in both systems) Login in a 4.5 (main) site in the app and go to User menu > Files. Long press the icon of any file. It should transform every icon into a checkbox and the header should count how many files has selected by the user. Select one or multiple files and remove them by pressing the "Trash" icon of the top right corner. The download button appears next to the context menu (3 dots). If a file is downloaded, you can delete the downloaded file using the 3 dots > Remove downloaded data. Delete an offline file individually using the options menu of the file, pressing "Delete". As teacher, go to "Site files" and search for files (e.g. in our master site you can find some in Issue testing > Isabel > Moodle triaging > Course section summaries > MDL-41090 ). Check that you cannot delete site files. Login in a 4.4 or older sites and check that you cannot delete private files. Download a private file in the app, login in LMS with the same user, go to private files and update the license of the file that you just downloaded in the app previously. Now when the user do a PTR in the app, should be able to update the downloaded file by pressing the cloud refresh icon.