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

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

2 Likes
3

Hey Matt,

Thanks a lot for sharing the link with the solution! It was exactly what I needed.

Funny how this was a perfect example of overthinking the issue and missing a simple fix. Sometimes we just need a nudge in the right direction!

I appreciate you taking the time to help out. :raising_hands:

Cheers,
Wilson

2 Likes