NetworkOffline when you start a session with no network. It returns OfflineSaveFailed when submit cannot save an offline session in IndexedDB.
These are Headless errors. Mobile SDK offline upload uses different event names. See Offline upload failures on Mobile SDK for that path.
Common causes
- No network when you call start.
- IndexedDB is full, blocked, or unavailable on submit.
- Private browsing or a policy that blocks storage for your site.
- Closing the SDK after
OfflineSaveFailedbefore you retry submit.
Fix NetworkOffline
1
Check the Network
Restore connectivity, then retry start.
2
Confirm the Error Shape
On Platform Client, look for
code: "StartSessionFailed" and reason: "NetworkOffline". In React, start may throw a string that includes those values.3
Retry After Reconnect
When the network returns, start again.
Fix OfflineSaveFailed
1
Free Browser Storage
Clear cache or IndexedDB for your origin if storage is full, then retry submit.
2
Retry Submit While the Session Is Open
If you close the SDK after
OfflineSaveFailed without a successful save, session data can be lost. Retry submit first.3
Check IndexedDB Access
Confirm the browser allows persistent storage for your site (including private mode and enterprise policies).
Next steps
Headless Web SDK error handling -NetworkOffline, OfflineSaveFailed, and related start or submit errors
Offline upload failures on Mobile SDK - Mobile offline buffer and upload events
Manage ambient session - Start, pause, resume, and submit
Microphone permission denied - AudioRecorderFailure on start or resume
sessionAlreadyExists - Remote ambient conflicts on create