diff --git a/devdocs/build/RELEASE-PROCEDURE.md b/devdocs/build/RELEASE-PROCEDURE.md
index 3fb077ed..e9fe58b8 100644
--- a/devdocs/build/RELEASE-PROCEDURE.md
+++ b/devdocs/build/RELEASE-PROCEDURE.md
@@ -257,7 +257,7 @@ new code. Set the new version in:
 | raven | `dist/install/windows/x64/lan.iss` | `#define MyAppVersion` |
 | raven | `dist/install/windows/x64/standalone.iss` | `#define MyAppVersion` |
 | raven | `dist/latest-version.json` | `latestversion` and the `changelogurl` anchor |
-| raven | `docs/8.0/ayanova/docs/changelog.md` | new version heading with "IN PROGRESS" under it |
+| raven | `docs/8.0/ayanova/docs/changelog.md` | new version heading; under it the "Upgrading from 8.2.4 or older?" line copied from the previous version's section (case 4759; keep it until John decides enough customers are past 8.3.0), then "IN PROGRESS" |
 | raven | `docs/8.0/ayanova/docs/ay-about.md` | the example version number |
 | raven-client | `ayanova/package.json`, `ayanova/package-lock.json` | `"version"` (both places in the lock file) |
 | raven-client | `ayanova/src/api/ayanova-version.js` | `version` |
diff --git a/docs/8.0/ayanova/docs/changelog.md b/docs/8.0/ayanova/docs/changelog.md
index b0f10aad..729007b8 100644
--- a/docs/8.0/ayanova/docs/changelog.md
+++ b/docs/8.0/ayanova/docs/changelog.md
@@ -10,6 +10,8 @@ See the [upgrade instructions](ops-upgrade.md) section of this manual for detail
 
 ### AyaNova 8.3.1
 
+**Upgrading from 8.2.4 or older?** AyaNova 8.3.0 and newer need a one-time [pre-upgrade step](ops-upgrade.md#upgrading-from-824-or-older) on Windows network and Linux installations.
+
 IN PROGRESS
 
 **Changed**
diff --git a/docs/8.0/ayanova/docs/ops-upgrade-linux-desktop.md b/docs/8.0/ayanova/docs/ops-upgrade-linux-desktop.md
index 805778ee..e2352616 100644
--- a/docs/8.0/ayanova/docs/ops-upgrade-linux-desktop.md
+++ b/docs/8.0/ayanova/docs/ops-upgrade-linux-desktop.md
@@ -43,13 +43,14 @@ After this step has completed you can continue with the normal upgrade process i
 
 #### upgrade script
 
-The following shell script will automatically remove the old AyaNova files, download and unzip the latest AyaNova files then start the server.
+The following shell script will automatically remove the old AyaNova files, download and unzip the latest AyaNova files then start the server. It first checks that the .NET 10 runtime is installed and stops without changing anything if it is not (see the pre-upgrade step above). If the download fails, it also stops before any files are removed.
 
 From a terminal window run the following commands:
 
 ```bash
 cd /opt/ayanova && \
-sudo curl -O https://www.ayanova.com/download/ayanova-linux-x64-desktop.zip && \
+{ dotnet --list-runtimes | grep -q '^Microsoft.AspNetCore.App 10\.' || { echo "The .NET 10 runtime is not installed: do the pre-upgrade step first. Nothing was changed."; false; }; } && \
+sudo curl -fO https://www.ayanova.com/download/ayanova-linux-x64-desktop.zip && \
 sudo rm *.dll && \
 sudo rm -r ./resource && \
 sudo rm -r ./wwwroot && \
diff --git a/docs/8.0/ayanova/docs/ops-upgrade-linux-server.md b/docs/8.0/ayanova/docs/ops-upgrade-linux-server.md
index f67a703b..fee4b690 100644
--- a/docs/8.0/ayanova/docs/ops-upgrade-linux-server.md
+++ b/docs/8.0/ayanova/docs/ops-upgrade-linux-server.md
@@ -59,12 +59,13 @@ After this step has completed you can continue with the normal upgrade process i
 
 #### upgrade script
 
-The following shell script will automatically stop the AyaNova server service, remove the old AyaNova files, download and unzip the latest AyaNova files then start the server service.
+The following shell script will automatically stop the AyaNova server service, remove the old AyaNova files, download and unzip the latest AyaNova files then start the server service. It first checks that the .NET 10 runtime is installed and stops without changing anything if it is not (see the pre-upgrade step above).
 
 Run the following shell commands:
 
 ```bash
 cd /var/ayanova && \
+{ dotnet --list-runtimes | grep -q '^Microsoft.AspNetCore.App 10\.' || { echo "The .NET 10 runtime is not installed: do the pre-upgrade step first. Nothing was changed."; false; }; } && \
 sudo systemctl stop ayanova.service && \
 sudo curl -fO https://www.ayanova.com/download/ayanova-linux-x64-server.zip && \
 sudo rm *.dll && \
diff --git a/docs/8.0/ayanova/docs/ops-upgrade.md b/docs/8.0/ayanova/docs/ops-upgrade.md
index 2a27d03b..87b3d8d2 100644
--- a/docs/8.0/ayanova/docs/ops-upgrade.md
+++ b/docs/8.0/ayanova/docs/ops-upgrade.md
@@ -4,6 +4,10 @@
 
 [View Change log / release notes](https://ayanova.com/docs/changelog).
 
+## Upgrading from 8.2.4 or older
+
+AyaNova 8.3.0 moved to .NET 10. If your AyaNova is version 8.2.4 or older, upgrading a Windows network (IIS or LAN) or Linux installation needs a one-time pre-upgrade step, described in the instructions for your platform below. It applies whichever newer version you upgrade to. Windows single standalone installations need no extra step.
+
 ## Maintenance plan
 
 AyaNova updates are available with an active Maintenance plan.