The actual revision of the List Item does not match the expected revision.
- Your update to this Sync List Item has conflicted with a request submitted elsewhere.
- The value specified in the If-Match header is erroneous.
The value you provide in the If-Match header should be a revision assigned by the Sync service when interacting with the object.
- In SDKs, this is the
revisionfield, part of the object descriptor.
- When using REST (e.g. via the Twilio Helper libraries) this is the
ETagheader provided in responses.