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# System prepended metadata

title: Summary

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# Summary

- The DataHighway parachain was down on the 12th november 2022
- This was generated by a GRANDPA error
- The solution achieved by upgrading the substrate version

# What happened

The polkadot team updated GRANDPA module, their concensus mechanism feature. Unfortunatley this brought  down multiple parachains, including ours. We realize that to solve the problem, we need to upgrade the substrate version to at least 0.9.26 version. Our next release (3.7.1) will be using substrate version 0.9.29. As soon as this is done, the chain and its collators can run again.

This issue only affects collators that have joined our parachain before the 15-11-22

# As an affected collator, how to solve this issue?

- Make sure they are running binary from here: https://github.com/DataHighway-DHX/DataHighway-Parachain/releases/tag/v3.7.1
- Make sure their parachain db ( located at /home/deployer/.local/share/datahighway-collator/chains/datahighway-tanganika-kusama-parachain/ is synced by our old binary)
- Changing the session key ( author.rotateKeys rpc call ) might also be helpful
- Passing the correct bootnode and make sure parachain is peering
