> ## Documentation Index
> Fetch the complete documentation index at: https://sidiorresearchlabs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Rollback

# Rollback

Learn how to rollback the chain version in the case of an unsuccessful chain upgrade.

In order to restore a previous chain version, the following data must be recovered by validators:

* the database that contains the state of the previous chain (in `~/.hyperpaxd/data` by default)
* the `priv_validator_state.json` file of the validator (also in `~/.hyperpaxd/data` by default)

If validators don't possess their database data, another validator should share a copy of the database. Validators will
be able to download a copy of the data and verify it before starting their node. If validators don't have the backup
`priv_validator_state.json` file, then those validators will not have double-sign protection on their first block.

## Restoring State Procedure

1. First, stop your node.

2. Then, copy the contents of your backup data directory back to the `HyperPaxeer_HOME/data` directory (which, by default,
   should be `~/.hyperpaxd/data`).

```bash theme={null}
# Assumes backup is stored in "backup" directory
rm -rf ~/.hyperpaxd/data
mv backup/.hyperpaxd/data ~/.hyperpaxd/data
```

3. Next, install the previous version of HyperPaxeer.

```bash theme={null}
# from HyperPaxeer directory
git checkout <prev_version>
make install
## verify version
hyperpaxd version --long
```

4. Finally, start the node.

```bash theme={null}
hyperpaxd start
```