Check the value of your " Maximum uploaded file size (maxbytes " setting in the site administration. You may want to set this to a small value for easier testing (e.g. 5MB). Go to a content bank and upload interactive-video.h5p . Edit interactive video content. Under " Add a video ", upload a video file with a size greater than the "maxbytes" setting. Confirm that you get the message: "The file x is too large. The maximum size you can upload is n." Try to upload a file that is smaller than the "maxbytes" setting. Confirm that the upload succeeds Antivirus test Install ClamAV e.g. on Ubuntu sudo apt update sudo apt install -y clamav sudo freshclam Get the path of the clamscan executable (e.g. " which clamscan "). Take note of this path. Open a new browser window/tab and go to " Site administration / Plugins / Antivirus plugins / Manage antivirus plugins " Enable ClamAV antivirus. Go to its Settings page Enter the path to the clamscan executable in " Command line ". Set " On ClamAV failure ", set it to " Refues upload, try again ". Save the changes. Download this anti-malware test file eicarcom2.zip . Rename it as " eicarcom2.mp4 " Back on the interactive video editor's browser window, attempt to upload the anti-malware test file. Confirm that after a little while, it will show an error that it has been scanned by a virus checker and found to be infected.