# X_REPLICATION_SLOT_INVALIDATED

## Means

the replication slot was invalidated

## Typical cause

postgres invalidated the replicator's slot (wal_status = lost): it fell further behind than max_slot_wal_keep_size allows, so the WAL it needed is gone and it can never stream again

## Fix

`SELECT pg_drop_replication_slot('<slot>');` — then restart the replicator: it recreates the slot and every live window resyncs

[Realtime](/error-codes#realtime)