FailedToSchedule

The scheduler could not place the call into the agenda, typically because the target block's agenda is full or the schedule parameters are unusable. Check Agenda at the target block against MaxScheduledPerBlock and pick a different block if it is saturated.

Declared by the Scheduler pallet; it classifies to the semantic code internal.

Remediation

A chain-side invariant failed; nothing to fix client-side — report it if it persists

The same explanation is available in the terminal: btcli explain FailedToSchedule.