# Restore failing with missing chat\_mention function

**URL:** https://meta.discourse.org/t/restore-failing-with-missing-chat-mention-function/331376
**Category:** Bug
**Tags:** fixed
**Created:** [October 17, 2024, 3:18pm UTC](https://meta.discourse.org/t/restore-failing-with-missing-chat-mention-function/331376 "2024-10-17T15:18:47Z")
**Posts on this page:** 1
**Showing post:** 17

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### Author: ![RGJ](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/rgj/32/523185_2.png) [@RGJ](https://meta.discourse.org/u/RGJ)
#### Post date: [October 21, 2024, 8:33am UTC](https://meta.discourse.org/t/restore-failing-with-missing-chat-mention-function/331376/17 "2024-10-21T08:33:53Z")

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The problem is that a [migration with an older date stamp](https://github.com/discourse/discourse/commit/8016fcab332a2945bc3ad9676111841af3bc7fee) was committed into tests-passed later on (@nbianca FYI), and this is not detected by the version metadata in the backup. I’ve kind of mentioned that [here](https://meta.discourse.org/t/pg13-compatibility-issue/331068/14).

> [@kendoer](#):
>
> rebuild app to get the old server to the exact same version as the new installation.

This is the solution. So you either need to get the commit hash from the instance server and build your new instance with that commit, or update the existing instance to latest, which will run that migration, and then take a new backup.

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