We have identified and remediated the underlying cause of the upload issues. We are monitoring to ensure no further impact is observed. If you are still seeing upload issues, please reach out at https://support.box.com
Additionally, to clarify the impact of the issue: from approximately 5:02 PM to 6:30 PM Pacific, a subset of users may have seen issues when uploading (>100MB files) to Box. Furthermore, during the same time, some users may have noticed delays with new file conversions and previews.