This issue occurs if all of the datastores in the storage profile selected during the upload are in the red threshold.
Resolution
To resolve this issue, either add storage that is not in a red threshold state to the profile, or change the thresholds in the existing datastores to allow a more tolerable threshold.
To change the thresholds:
Log in to the vCloud Web UI as a System Administrator and click the Manage & Monitor tab.
Navigate to vSphere Resources > Datastores & Datastore Clusters.
Right-click on one of the datastores in the desired Storage Profile and select Properties.
Under Status and Thresholds, adjust the Disk space threshold yellow: and Disk space threshold red: accordingly and click OK.
Try the Upload Media task again and the media upload should now be successful.