Permissions : Custom role with permissions to manage users, roles and permissions is unable to assign roles to users

This article explains the defect in Sitefinity where users with valid permissions are unable to assign roles to users due to "Value cannot be null. Parameter name: name" error alert

Dec 1, 2025
Knowledge

Title

URL Name

permissions-custom-role-with-permissions-to-manage-users-roles-and-permissions-is-unable-to-assign-roles-to-users

Article Number

000294759

Environment

Product: Sitefinity Version: 13.3, 14.4, 15.x OS: All supported OS versions Database: All supported Microsoft SQL Server versions

Question/Problem Description

A user with a custom role having permissions to manage users, user profiles, roles, and permissions, along with other roles, is unable to edit the roles assigned to an existing user if they already have different roles assigned to them.

Users with the custom role also see a browser alert with a "Value cannot be null. Parameter name: name" error

Steps to Reproduce

1. Create a custom role by going to Administration> Roles (Ex: MyRole) 2. Assign all the permissions associated with Managing Users, Roles, Permissions and User Profiles to the new role 3. Create a new user and assign him the above role along with other roles (Eg: Role A, Role B) 4. Log in as the new user and try to edit an existing user who is already assigned to a few roles (Eg: Role C, Role D) Expected: The user edit screen should open, and upon assigning one of the roles that the editing user already has and clicking on "Save Changes", the roles should be assigned to the user. Actual: A browser alert with error "Value cannot be null.Parameter name: name" is thrown when the user edit screen is loaded. After closing the alert and assigning roles(already assigned to the editing user) to the user, an error "You do not have the permissions to perform this action. Contact your system administrator for assistance." is thrown

Clarifying Information

Error Message

Value cannot be null.Parameter name: name

Defect Number

571872

Enhancement Number

Cause

The issue is caused by a bug in Sitefinity

Resolution

Fixed in:

Sitefinity Patch 15.4.8623

Refer to Knowledge Base Article How to update Sitefinity to hotfix, internal build or a patch for instructions on how to download and install the fix.
None at this time.

Workaround

Notes

Keyword Phrase

Last Modified Date

3/5/2026 9:07 AM

Permissions : Custom role with permissions to manage users, roles and permissions is unable to assign roles to users

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