Unable to upgrade to a newer 15.4 patch version, the application fails to initialize with a System.ValueTuple assembly load failure. The failure occurs during Sitefinity bootstrap, specifically during license validation (Progress.Sitefinity.AzureLicenseVault.KeyVaultLicenseProvider.Initialize) on Sitefinity Cloud, or during Azure Blob Storage initialization, or during System.Text.Json deserialization in custom code.

On Sitefinity Cloud, this manifests as a CI.CD pipeline warmup failure where the health check endpoint (restapi/health?type=m) returns 500 Internal Server Error continuously until the warmup times out.

On self-hosted environments, this appears as a following "Server Error in / Application" page:

Assembly mismatch. The Azure SDK libraries used by Sitefinity (Azure.Identity, Azure.Storage.Blobs, System.Text.Json) depend on System.ValueTuple assembly version 4.0.5.0. However, the project either has no System.ValueTuple NuGet package installed (relying on the .NET Framework built-in version 4.0.3.0) or has an older NuGet package version with a binding redirect that does not cover version 4.0.5.0.

1. Upgrade the System.ValueTuple NuGet package in the Sitefinity CMS project to version 4.6.2:
   
   

   NuGet\Install-Package System.ValueTuple -Version 4.6.2

2. After the package update, verify the System.ValueTuple binding redirect in web.config. Ensure the newVersion is set to 4.0.5.0 and the oldVersion range covers all versions up to 4.0.5.0:
   

   <dependentAssembly>
     <assemblyIdentity name="System.ValueTuple" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
     <bindingRedirect oldVersion="0.0.0.0-4.0.5.0" newVersion="4.0.5.0" />
   </dependentAssembly>

    

   Check in .csproj file to make sure the following entry is configured as follows:
   

   <Reference Include="System.ValueTuple, Version=4.0.5.0, ..."> with HintPath ..\packages\System.ValueTuple.4.6.1\lib\net47\System.ValueTuple.dll

3. Commit the changes and deploy:

   • For Sitefinity Cloud: push to the main branch and run the CI/CD pipeline with Partial Deployment unchecked (full deployment).
   • For self-hosted: deploy the updated bin folder and web.config to the server.

4. If the application still fails to start after steps 1-3, remove the System.ValueTuple dependentAssembly binding redirect block entirely from web.config, then commit and deploy again.

• For Sitefinity Cloud projects where direct NuGet package management is not possible through the cloud repository, take a local copy of the main branch, perform the upgrade locally in Visual Studio, then merge the changes back to the main branch and run the CI/CD pipeline.
• In some projects, if the build fails after upgrading System.ValueTuple, the Azure.Identity NuGet package and its dependencies may also need to be updated to compatible versions. All Azure SDK binding redirects in web.config should be updated accordingly.

Progress Article(s):

1. Upgrade: The home page is throwing a 500 error (/500-error?aspxerrorpath=/)