InvalidOperationException when opening the Inheritance tab of a template under the /sitecore/templates/System/Forms/Fields node


Description

Accessing the Inheritance tab of a template located under the /sitecore/templates/System/Forms/Fields node might fail with an unhandled exception:

[InvalidOperationException: fieldTypeItem]
   Sitecore.Shell.Applications.Templates.TemplateInheritance.TemplateInheritanceForm.RenderTemplate(HtmlTextWriter output, ID templateID, Set`1 collisions) +1671
   Sitecore.Shell.Applications.Templates.TemplateInheritance.TemplateInheritanceForm.RenderTemplate(HtmlTextWriter output, Template template, Set`1 collisions) +127
   Sitecore.Shell.Applications.Templates.TemplateInheritance.TemplateInheritanceForm.RenderTemplate(HtmlTextWriter output, ID templateID, Set`1 collisions) +1396
   Sitecore.Shell.Applications.Templates.TemplateInheritance.TemplateInheritanceForm.RenderTemplate(HtmlTextWriter output, Template template, Set`1 collisions) +127
   Sitecore.Shell.Applications.Templates.TemplateInheritance.TemplateInheritanceForm.OnLoad(EventArgs e) +379

The issue affects the Sitecore XM Scaled (XM1) and XM Single (XM0) topologies.

The root cause of the issue is missing items under the /sitecore/system/Field types/Developer Types node in the Core database in the XM topology, namely /sitecore/system/Field types/Developer Types/JSON and /sitecore/system/Field types/Developer Types/Sitecore User.

Solution

To resolve the issue, download and install the following package that contains the missing items: