[Minor] Issues with Uploads

Final update

We recently addressed issues affecting file uploads in Box. We would like to take the opportunity to further explain these issues and the steps we have taken to keep them from happening in the future. Between 4:47 AM PDT and 5:28 AM PDT on June 24, 2026, some users may have experienced difficulties uploading larger files to Box. During this time, chunked uploads of large files may have failed or timed out, while smaller file uploads continued to work normally. The issue occurred when an internal system that temporarily tracks the progress of large, chunked uploads experienced an unexpected failover and lost the in-progress upload information it was holding. The issue resolved once those connections were reset. In addition, we are hardening how our upload service detects and recovers from this kind of interruption to prevent similar issues in the future. # Analysis Large file uploads in Box are split into multiple parts and rely on a shared internal caching system to track the progress of each upload while it is in flight. During this incident, that caching system underwent an unexpected failover, and the newly promoted instance did not contain all of the in-progress upload state. A

1. Postmortem · Jun 29, 18:26 UTC
   We recently addressed issues affecting file uploads in Box. We would like to take the opportunity to further explain these issues and the steps we have taken to keep them from happening in the future. Between 4:47 AM PDT and 5:28 AM PDT on June 24, 2026, some users may have experienced difficulties uploading larger files to Box. During this time, chunked uploads of large files may have failed or timed out, while smaller file uploads continued to work normally. The issue occurred when an internal system that temporarily tracks the progress of large, chunked uploads experienced an unexpected failover and lost the in-progress upload information it was holding. The issue resolved once those connections were reset. In addition, we are hardening how our upload service detects and recovers from this kind of interruption to prevent similar issues in the future. # Analysis Large file uploads in Box are split into multiple parts and rely on a shared internal caching system to track the progress of each upload while it is in flight. During this incident, that caching system underwent an unexpected failover, and the newly promoted instance did not contain all of the in-progress upload state. As a result, affected sessions could not continue and returned errors. Recovery was further delayed because the upload service continued to use a connection that was no longer valid. Standard file uploads do not depend on this system and were not affected. ## Corrective Actions Box has initiated the
2. Resolved · Jun 24, 12:33 UTC
   This incident is now considered resolved. Box uploads have been restored to full functionality. Please contact Box Support at https://support.box.com/ if you continue to experience any issues.
3. Investigating · Jun 24, 12:18 UTC
   We are investigating an ongoing issue affecting uploads. We will provide more information as soon as it is available.