409 Conflict
Situations in the vault where SharePoint, SPFx, Microsoft Graph or the Azure services around them answer with HTTP 409. Each one explains why it happens and how to fix it.
- Two MERGEs to the same list item at once: the second one fails with 409 Save Conflict even with IF-MATCH: * – and a fire-and-forget write just disappearsgotchas / rest-apiIF-MATCH: * only switches off the ETag check (412); SharePoint still refuses a second save of the same item while the first is in flight with 409 Save Conflict. Queue writes per item (list#id), retry 409 briefly, never…
- Creating a modern page via REST is a three-step dance, not one POSTgotchas / rest-apiCanvasContent1 won't stick on create; create → SavePageAsDraft → Publish, canvas is JSON; plain JSON is enough, Description needs its own write and a re-publish; the file name is random — rename with moveto