Umbraco 13.8.1 + Forms 13.4.2: "Unable to resolve service for type 'IFormService'" and 'IFormsSecurity' on startup after upgrade

Questions
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1

Hi everyone,

I’m struggling with a blocking error after upgrading my solution from Umbraco 11 to Umbraco 13. My setup is:

  • Umbraco CMS: 13.8.1
  • Umbraco Forms: 13.4.2
  • .NET: 8.0
  • Project type: Upgrade/migration from Umbraco 11, not a clean install.

The error:
System.AggregateException: Some services are not able to be constructed
(Error while validating the service descriptor ‘ServiceType: Umbraco.Forms.Core.PropertyEditors.ValueConverters.FormPickerValueConverter Lifetime: Singleton ImplementationType: Umbraco.Forms.Core.PropertyEditors.ValueConverters.FormPickerValueConverter’:
Unable to resolve service for type ‘Umbraco.Forms.Core.Services.IFormService’ while attempting to activate ‘Umbraco.Forms.Core.PropertyEditors.ValueConverters.FormPickerValueConverter’.)
(Error while validating the service descriptor ‘ServiceType: Umbraco.Forms.Web.Trees.FormTreeController Lifetime: Scoped ImplementationType: Umbraco.Forms.Web.Trees.FormTreeController’:
Unable to resolve service for type ‘Umbraco.Forms.Core.Security.IFormsSecurity’ while attempting to activate ‘Umbraco.Forms.Web.Trees.FormTreeController’.)

This always occurs on application startup and prevents Umbraco from booting at all.

What I’ve tried / Troubleshooting steps:

  • Confirmed NuGet packages: Umbraco.Cms at 13.8.1, Umbraco.Forms at 13.4.2, nothing custom in Forms, all references look correct.
  • Full clean and rebuild, manual wipe of /bin and /obj.
  • If Forms is present, Umbraco won’t start, always hitting the error above (so I never get a dashboard, even after a full DB restore or upgrade).
  • Database: Tried both with and without the Forms tables (UF*); same error. Also tried removing the Umbraco.Core.Upgrader.State+UmbracoForms row from [umbracoKeyValue] and letting the installer recreate it. The Forms tables are never (re)created—installer doesn’t run.
  • Connection strings are correct.
  • No custom DI code related to Forms.
  • No extra configuration or custom value converters registered.

Extra context:
The error message refers to both IFormService and IFormsSecurity being unresolvable.
This is not a fresh install—my solution was upgraded from Umbraco 11, and Forms worked fine there.

Questions:

  • Has anyone seen this “Unable to resolve service for type” for both IFormService and IFormsSecurity in this upgrade scenario?
  • Are there any known DI/lifetime issues (singleton/scoped) with Umbraco Forms 13.4.2?
  • Is there something extra required for Forms to register its services correctly in 13.x after an upgrade?
  • Are there steps I should do differently to re-initialize Forms tables after an upgrade?

Any tips, or even a pointer to where to debug further, would be very helpful!

Thanks in advance,
Wilson

2

Hi Wilson,

Have you seen this post which

https://forum.umbraco.com/t/system-aggregateexception-after-installing-umbraco/3815?u=mattw

It looks to be the same or similar error, and they are posting on why they had it and the solution

Hope this helps
Matt