Multi Site NuGet v2 for Optimizely CMS 13 – Breaking Changes & Migration

Posted on Saturday, February 21, 2026

The beta version 2 of DavidHome.Optimizely.MultiSite is now available on NuGet: https://www.nuget.org/packages?q=DavidHome.Optimizely.MultiSite

This is a major upgrade compatible with Optimizely CMS 13 preview. Version 1 of this plugin will remain available and compatible with CMS 12. Both versions are planned to be supported until either Optimizely announces they no longer support the old version or that the disparity of feature between CMS 12 and 13 is making it complicated to maintain the plugin for both versions. 

What Changed in v2

Starting with CMS 13, multi-site resolution is based on the Application identity (internal / normalized name) instead of the display name.

This means folder resolution, asset handling, and UI grouping no longer rely on the display name of the site.

Breaking Change When Upgrading

If your CMS 12 website configuration included spaces in the site name, you must now use the normalized internal name under CMS 13.

Example:
Display name (CMS 12): My Corporate Website
Normalized Application ID (CMS 13): mycorporatewebsite

Folder structure must now follow the normalized name:
Incorrect (old style): wwwroot/My Corporate Website/
Correct (CMS 13 style): wwwroot/mycorporatewebsite/

If you upgrade to v2, every area of the plugin that relies on the site name must be updated accordingly.

This includes:

  • Static asset folders
  • Category mapping
  • UI grouping
  • Automation or deployment scripts
  • Any name-based conventions

Technical Prerequisites

  • .NET 10 target framework
  • CMS dependency 13.0.0-preview2+

More Information

Initial announcement post: https://www.davidhome.net/blog/optimizely-cms-multi-site-setup

Source code and README: https://github.com/ddprince17/davidhome-optimizely-multisite

Final Notes

This release intentionally aligns with CMS 13 architecture. If you are upgrading from version 1, review your website configuration names and folder structures carefully before deploying to production.

Feedback and migration experiences are always welcome.