The send was not attempted. Unibox shows "Blocked by Account Protection: {reason}. The send was not attempted." Fix the named reason, then retry.
Read the reason, then open that page
Account Protection always runs before LinkedIn. The banner is the source of truth.
Copy the reason after Blocked by Account Protection.
Match it in the table below.
Open that page and fix the control.
Return to Unibox or the campaign and retry. Do not retry in a loop while the same reason is still true.
If the banner still names the same reason, the control did not save or you opened the wrong workspace.
A campaign launch can fail the same gates during Review preflight. Fix the sender or workspace first, then open Review again. The send is never handed to LinkedIn while the reason is true. No seat is a badge, not a status, and it still blocks. The kill switch on Settings → General is the workspace-wide halt. Travel mode and the circuit breaker live on the sender and on Settings → Safety.