I am trying to generate raw chain spec from plain chain spec, but it won't let me:

✗ ./target/release/node-template build-spec --chain plain-local-chainspec.json --raw > chain-spec.json
Error: Input("Error parsing spec file: unknown field `forkBlocks` at line 201 column 1"

error in terminal

Has anyone else had this? How have you resolved the issue?

1 Answer 1


I think one of the node or the spec file is outdated.

The node can not parse the spec file correctly.

You could try generating a new spec file using the node.

Or go to the spec file line 201, and delete the deprecated field forkBlocks.

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