Signature error on polkadot js

[kamilsa]

No description provided.

[Harrm]

This error occurs when finalization is lagging (but no more than for 512 blocks, after this threshold we have another error). It is worth noticing that extrinsic submition works when performed through python substrate interface in this scenario, only extrinsic generated via Polkadot JS fail with the signature error. It could be connected to the fact that Polkadot JS receives a lot of data that it allegedly uses to construct an extrinsic via subscription on storage keys, while python substrate interface fetches this data directly.

[turuslan]

polkadot-js/apps uses finalized block for mortality. However mortality Era uses lossy encoding, which becomes incorrect if finalized block is too far from best block.

https://github.com/paritytech/polkadot-sdk/blob/8f8297e9debe79139e3a41be8b54a5fcd603f783/substrate/frame/system/src/extensions/check_mortality.rs#L59-L75