I have changed the name on my spec.json and I am getting this erro

Unable to author block in slot 270671004,. `can_author_with` returned: `spec_name` does not match `X` vs `node-frontier-template` Probably a node update is required!

Edit :

I have changed this too !

pub const VERSION: RuntimeVersion = RuntimeVersion {
    spec_name: create_runtime_str!("x"),
    impl_name: create_runtime_str!("x"),
    authoring_version: 1,
    spec_version: 1,
    impl_version: 1,
    transaction_version: 1,
    state_version: 1,

What would be the issue behind?

1 Answer 1


Take Polkadot as an example.

You can not change the spec name in runtime lib.rs, nor the one in spec file polkadot.json during the chain is running.

IIUC, if you want to change it, you need to start a new chain. Otherwise, you might need to do a lot of extra work.

  • 1
    Try to clean the DB, and start a dev chain. If you are developing a new chain. Sep 2, 2022 at 11:05
  • Indeed I've changed create_runtime_str in lib.rs. Should I keep it as it was or there is a way around to change it too?
    – katapulte
    Sep 2, 2022 at 12:00
  • If you want to continue working with the previous one, revert that changes. Otherwise, you could keep the changes and start a new chain. Sep 3, 2022 at 8:50
  • I am facing the issue while starting a new chain
    – katapulte
    Sep 3, 2022 at 20:38
  • Could you provide more detail? Like, what's your boot command? What changes did you do? Sep 4, 2022 at 4:57

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