How to re-upload a Panopto video after a failed upload:
Go into "Managed Recordings"

Set failed video to “Offline"

Click “Upload to Server" again.

Click “Add New Session”

Give the session a new name, if you want, and click “Upload New Session”

Large videos can take a long time to upload, if you have to leave the room it is ok to log-out of your profile, the video will upload in the background.
Warning: do not shut down the computer or it will cause the video to fail on upload.