#troubleshooting 5 articles

• "Search finds nothing here" is usually a site missing from the index — not a permissions problemgotchas / searchThree queries tell you whether the site is in the index at all, before you debug a query that was never wrong
• Adding or removing a group member via Graph needs the object ID — a UPN returns 400 "Invalid object identifier"gotchas / graphPOST /groups/{id}/members/$ref and DELETE /groups/{id}/members/{id}/$ref accept only the user's object ID (GUID); a UPN from a people picker returns 400 Invalid object identifier — resolve it with GET…
• directoryObject collections reject $select of user fields — and $top is a separate, per-endpoint trapgotchas / graphUser fields on /members//transitiveMembers = 400; OData cast cures $select everywhere, $top stays per-endpoint (probe both)
• Fewer sites and sudden 403s usually mean a different account, not a tenant outagegotchas / securityA tenant-wide snippet run from a second browser window executes as whoever is signed in there; print currentuser and the visible-site count before you blame the tenant
• Microsoft To Do rejects $select on lists and tasks — 400 invalidRequest (RequestBroker--ParseUri)gotchas / graphSince Oct 2026 /me/todo/lists and /tasks return 400 for any $select except id; drop $select, keep $top/$filter, and measure 400s call by call before trusting a docs-based theory