diff --git a/source/upgrade/important-upgrade-notes.rst b/source/upgrade/important-upgrade-notes.rst
index cafe4b0954c..f7e6accdeac 100644
--- a/source/upgrade/important-upgrade-notes.rst
+++ b/source/upgrade/important-upgrade-notes.rst
@@ -16,7 +16,15 @@ Important Upgrade Notes
 | If you’re upgrading                                | Then...                                                                                                                                                          |
 | from a version earlier than...                     |                                                                                                                                                                  |
 +====================================================+==================================================================================================================================================================+
-| v10.5                                              | As part of the Property System Architecture feature, Mattermost v10.5 is going to run a set of migrations to add new tables to the schema. This migration only   |
+| v10.5                                              | The Mattermost server has stopped supporting manual plugin deployment. Plugins are deployed manually when an administrator or some deployment automation copies  |
+|                                                    | the contents of a plugin bundle into the server's working directory. If a manual or automated deployment workflow is still required, administrators can instead  |
+|                                                    | prepackage the plugin bundles. See more details in `this forum post <https://forum.mattermost.com/t/deprecation-notice-manual-plugin-deployment/21192>`__.       |
+|                                                    +------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+|                                                    | Mattermost has stopped official Mattermost server builds for the Microsoft Windows operating system. Administrators should migrate existing Mattermost server    |
+|                                                    | installations to use the official Linux builds. See more details in                                                                                              |
+|                                                    | `this forum post <https://forum.mattermost.com/t/deprecation-notice-server-builds-for-microsoft-windows/21498>`__.                                               |
+|                                                    +------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+|                                                    | As part of the Property System Architecture feature, Mattermost v10.5 is going to run a set of migrations to add new tables to the schema. This migration only   |
 |                                                    | creates new tables and indexes, so there is no impact on preexisting data.                                                                                       |
 |                                                    |                                                                                                                                                                  |                                               
 |                                                    | New tables ``PropertyGroups``, ``PropertyFields`` and ``PropertyValues`` are going to be created.                                                                |