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How to upgrade from uSkinned Site Builder for Umbraco 8, 9, 10 or 11 to Umbraco 12

Latest compatible version: Umbraco 12.3.3 uSkinned Site Builder 5.2.0

Step 1

Create a new Umbraco 10 project and install uSkinned Site Builder 3.0.5 for Umbraco 10.

Follow our guide here if you are unsure how to do this.

Step 2

Install uSync against your new Umbraco 10 website.

dotnet add package uSync --version 10.7.1

Step 3

Run your website. This will generate uSync files which define the database records for your uSkinned Site Builder product.

Delete the contents of:

  • ~/uSync/{VERSION}/Content
  • ~/uSync/{VERSION}/Media

The reason you do this is because in a later step you are going to run a uSync content import to update Dictionary items in your existing Umbraco 8 database. You do not want to overwrite your content and media with the demo content that has been installed against your Umbraco 10 database.

Step 4

Go to your Umbraco 10 website directory and delete the contents of:


Go to your Umbraco 8 website and copy the contents of:


Paste your copied media into your Umbraco 10 website directory at location:


Step 5

Locate the following file within your Umbraco 10 website directory:


Update the connection string to point to your Umbraco 8 database.

Set UpgradeUnatended to true.

Set RunSchemaAndContentMigrations to false.

  "$schema": "",

  "ConnectionStrings": {
  "Umbraco": {
    "CMS": {
      "Unattended": {
        "UpgradeUnattended": true
"PackageMigration": {
"RunSchemaAndContentMigrations": false
} } } }

Step 6

Run your website and login to the Umbraco CMS. Dont worry if you see an error when browsing the frontend of your website at his stage.

Go to the Settings (Section) > uSync (node) > Import Settings

This will update Document Type and Data Type changes

Go to the Settings (Section) > uSync (node) > Import Content

This will update Dictionary item changes

When the settings import is complete your website will be upgraded to Umbraco 10.

Step 7

Re-save your Design node to generate the stylesheet for your website.

Step 8

Use the following SQL against your database to stop package migrations running each time you start your website:

INSERT [dbo].[umbracoKeyValue] ([key], [value], [updated]) VALUES (N'Umbraco.Core.Upgrader.State+uSkinned Site Builder', N'7620af66-17aa-494f-83bf-30ae13ce31c5', GETDATE())
INSERT [dbo].[umbracoKeyValue] ([key], [value], [updated]) VALUES (N'Umbraco.Core.Upgrader.State+uSkinned Site Builder - RTE App Settings', N'a4e56f62-8813-44d2-84dc-9eecdcee0b26', GETDATE())

Step 9

It is possible to upgrade from 10 to 12 using Nuget however we have found that some people have difficulty with this process. We therefore recommend creating a new Umbraco 12 website with the latest version of uSkinned Site Builder installed and repeat steps 1 to 7 above except this time you are moving from 10 to 12 instead of 8 to 10.

If you have completed the above steps to upgrade and experience any issues, please refer to the following troubleshooting solutions.


The following issues are a result of not following Step 1 in this guide and instead attempting to complete the upgrade process via NuGet.

Error in backoffice when viewing content nodes

'Sequence contains more than one matching element'

Caused by duplicate property editors which happen due to the presence of property editors found in the folder:


The property editors from this folder are now included with the Razor Class Libraries for Umbraco 10.

If you are using Umbraco Forms, delete the folder:


If you have upgraded via NuGet, delete the folder:


Now, rebuild your project and run.

Form Submission goes to a blank page with Javascript output

Javascript is broken due to a change in the file


Contact support for guidance on fixing this issue.


Step 1

Sign up

Start a free trial of Site Builder.

Step 2


Tailor the look and feel with the Visual Designer to suit your brand.

Step 3


Add content with built-in eCommerce and third-party integrations.

Step 4


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