Why do I get this error? application=indexer fetcher=block_catchup first_block_number=6 last_block_number=0 [error] ** (Postgrex.Error) ERROR 23505 (unique_violation) duplicate key value violates unique constraint "one_consensus_child_per_parent" and Key (parent_hash)=(\x0000000000000000000000000000000000000000000000000000000000000000) already exists ?

[Anilkumar18]

Key (parent_hash)=(\x0000000000000000000000000000000000000000000000000000000000000000) already exists.
(ecto_sql 3.10.1) lib/ecto/adapters/sql.ex:913: Ecto.Adapters.SQL.raise_sql_call_error/1
(ecto_sql 3.10.1) lib/ecto/adapters/sql.ex:803: Ecto.Adapters.SQL.insert_all/9
(ecto 3.10.2) lib/ecto/repo/schema.ex:59: Ecto.Repo.Schema.do_insert_all/7
(explorer 5.2.0) lib/explorer/repo.ex:61: anonymous fn/5 in Explorer.Repo.safe_insert_all/3
(elixir 1.14.5) lib/enum.ex:2468: Enum."-reduce/3-lists^foldl/2-0-"/3
(explorer 5.2.0) lib/explorer/chain/import.ex:303: Explorer.Chain.Import.insert_changes_list/3
(stdlib 4.0.1) timer.erl:235: :timer.tc/1
(explorer 5.2.0) lib/explorer/prometheus/instrumenter.ex:17: Explorer.Prometheus.Instrumenter.block_import_stage_runner/4

2023-10-18T15:17:08.395 application=indexer fetcher=block_catchup first_block_number=6 last_block_number=0 [error] ** (Postgrex.Error) ERROR 23505 (unique_violation) duplicate key value violates unique constraint "one_consensus_child_per_parent"

table: blocks
constraint: one_consensus_child_per_parent

Key (parent_hash)=(\x0000000000000000000000000000000000000000000000000000000000000000) already exists.
(ecto_sql 3.10.1) lib/ecto/adapters/sql.ex:913: Ecto.Adapters.SQL.raise_sql_call_error/1
(ecto_sql 3.10.1) lib/ecto/adapters/sql.ex:803: Ecto.Adapters.SQL.insert_all/9
(ecto 3.10.2) lib/ecto/repo/schema.ex:59: Ecto.Repo.Schema.do_insert_all/7
(explorer 5.2.0) lib/explorer/repo.ex:61: anonymous fn/5 in Explorer.Repo.safe_insert_all/3
(elixir 1.14.5) lib/enum.ex:2468: Enum."-reduce/3-lists^foldl/2-0-"/3
(explorer 5.2.0) lib/explorer/chain/import.ex:303: Explorer.Chain.Import.insert_changes_list/3
(stdlib 4.0.1) timer.erl:235: :timer.tc/1
(explorer 5.2.0) lib/explorer/prometheus/instrumenter.ex:17: Explorer.Prometheus.Instrumenter.block_import_stage_runner/4

[sl1depengwyn]

The reason is that there should be no blocks with the same parentHash field on the chain, however your chain has such blocks

Example of how it looks on ETH Mainnet