[main] [DOCS+] Add #158940 to the list of 8.8.0 known issues (#159197) (

#159221)

# Backport

This will backport the following commits from `8.8` to `main`:
- [[DOCS+] Add #158940 to the list of 8.8.0 known issues
(#159197)](#159197)

<!--- Backport version: 8.9.7 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

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Add #158940 to the list of 8.8.0 known issues (#159197)\n\nThis PR adds
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issues:\r\n* issue: https://github.com/elastic/kibana/issues/158733\r\n*
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Add #158940 to the list of 8.8.0 known issues (#159197)\n\nThis PR adds
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Co-authored-by: Gerard Soldevila <[email protected]>

docs/CHANGELOG.asciidoc

@@ -51,6 +51,21 @@ Review the following information about the {kib} 8.8.0 release.
 [[known-issues-8.8.0]]
 === Known issues
 
+// tag::known-issue-158940[]
+[discrete]
+.Failed upgrades to 8.8.0 can cause bootlooping and data loss
+[%collapsible]
+====
+*Details* +
+The 8.8.0 release splits the `.kibana` index into multiple saved object indices. If an upgrade to 8.8.0 partially succeeds, but not all the indices are created successfully, {kib} may be unable to successfully complete the upgrade on the next restart.
+
+This can result in a loss of saved objects during the upgrade. This can also leave {kib} in a bootlooping state where it's unable to start due to `write_blocked` indices.
+
+*Impact* +
+The 8.8.1 release includes in {kibana-pull}158940[a fix] for this problem. Customers affected by a failed 8.8.0 upgrade should contact Elastic support. For more information, see the {kibana-issue}58733[related issue].
+====
+// end::known-issue-158940[]
+
 // tag::known-issue-155203[]
 [discrete]
 .Monitors in Synthetics may stop running