# RUM application created, no sessions
What you see: the RUM application exists, the SDK is installed, and the sessions explorer is empty.
## Checklist
1. **clientToken and applicationId.** Both come from creating the application in the Datadog app. A token from app A pasted into app Bs snippet sends sessions nowhere you are looking. Re-copy both.
2. **Snippet placement.** The SDK must load on the pages you test. If it is behind a feature flag, a consent gate, or only on one route, your test page may not run it.
3. **Ad blockers.** They block the RUM SDK domain. Your test browser with uBlock on will show zero sessions while real users are fine. Test in a clean profile.
4. **Sample rates.** Session replay and session sample rates default to values that may drop everything at low traffic... check the init options: `sessionSampleRate` at 100 keeps everything while debugging.
5. **Content Security Policy.** A strict CSP can block the SDK script or its intake endpoints. Check the browser console for CSP violations.
6. **Wrong environment filter.** Sessions are there but you are filtering by an env the SDK is not sending. Clear filters first.
## Confirm
Open devtools on the page: the SDK should make network requests to the Datadog intake on load and on actions. No requests means the snippet never ran (placement, CSP, blocker). Requests with 4xx means the token/ID is wrong.
## Trap
Debugging with an ad blocker on and concluding the integration is broken. It is the number one false negative in RUM setup.