# Baikal failed backup when upgrading **URL:** \ **Category:** Support apps\ **Tags:** baikal, english\ **Created:** [February 19, 2026, 6:24pm UTC](https://forum.yunohost.org/t/baikal-failed-backup-when-upgrading/41622 "2026-02-19T18:24:39Z")\ **Posts on this page:** 1\ **Showing post:** 6
**Author:** ![Pinipon](https://forum.yunohost.org/letter_avatar_proxy/v4/letter/p/ea666f/32.png) [@Pinipon](https://forum.yunohost.org/u/Pinipon)\ **Post date:** [February 20, 2026, 4:15pm UTC](https://forum.yunohost.org/t/baikal-failed-backup-when-upgrading/41622/6 "2026-02-20T16:15:14Z")
Probably it’s an error related to php version, which had an issue recently due to expirated keys, you should be able to restore the previous backup, fix the issue and then update, check this: > [@Yarn and Sury APT keys issues](https://forum.yunohost.org/t/yarn-and-sury-apt-keys-issues/41617): > > Hi everyone ! You might have issues with your system updates wrench. Here are the usual error messages: W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://packages.sury.org/php bookworm InRelease: The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key W: GPG error: https://dl.yarnpkg.com/debian stable InRelease: The following signatures couldn’t be ve… > [@Something went wrong while updating the cache of APT (due to SURY) (version 2024)](https://forum.yunohost.org/t/something-went-wrong-while-updating-the-cache-of-apt-due-to-sury-version-2024/28570): > > uk/us What to do if you have an error while updating the repo ? I just had an error while trying to update my server : [multiple sources listed here] W: Some index files failed to download. They have been ignored, or old ones used instead. W: Failed to fetch https://packages.sury.org/php/dists/bullseye/InRelease The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key W: An error occurred during the signature verification. The repository is no… --- _[View the full topic](https://forum.yunohost.org/t/baikal-failed-backup-when-upgrading/41622)._