This was tested for Oqtane v4.0+ and works without issues.

Important: This will not work with Oqtane Source code version.

Pre-Requisites

1. You have Oqtane installed as a release-build (not in dev-mode) and a host account
2. Ensure you created backup of your web folder and sql database.
3. Ensure you have the .net Core 8 Hosting / Runtime installed on the server - for Oqtane 3 you only had v6, so if this is the first system you're upgrading, make sure this is done.
   1. to find out if it's installed, run dotnet --list-runtimes according to Microsoft
   2. After upgrading, you must restart IIS - eg using iisreset /restart.

Choose preferred Upgrade Path

Option 1: Automatic Upgrade using System Update

1. Login as host user and open Admin Dashboard / System Update
   
2. If Oqtane Framewrok is not already up to date, you can select the [Download] button to download the framework upgrade package and then select upgrade.
   
3. After several minutes, you can log in and check in Admin Dashboard / System Info that Oqtane version is upgraded.
   
   
   

Option 2: Manual Upgrade

1. Copy the wwwroot/app_offline.bak to the root folder and rename it to app_offline.htm.  Note that the new location is in the root folder, and not in wwwroot any more. Your website should now be offline (please verify)
2. Now get the Oqtane upgrade zip file from GitHub and unzip everything into the root folder, overwriting all DLLs and everything
3. Delete your app_offline.htm and visit your site again, everything should be upgraded

Afterwards: Install 2sxc (optional)

This is optional, but most Oqtane installations will also want to install 2sxc or upgrade 2sxc.

Note that going from Oqtane 4 - which runs older versions of 2sxc, you must upgrade to 2sxc 16.09+ or later. See compatibiity list.