---
schema_version: "1"
id: f38a7618178cc81a79a84a6355f1ab5eca5ca81f009e6d848e7c5dfa02c11473
title: Sandbox Users with Non-Unique Usernames Can't Be Unfrozen
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/release-notes/260-0-0/rn_security_username_uniqueness.md
canonical_url: https://help.salesforce.com/s/articleView?id=release-notes.rn_security_username_uniqueness.htm&release=260&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 349679305c8c13ea81d0f9cd785c0f4ea3ece39df0647c730841bb7fb625bbd1
description: You can't unfreeze a sandbox user if their username exists in another sandbox instance. This change prevents duplicate usernames for active, unfrozen users. To unfreeze a user with a non-unique username, update the username to a unique value.
products:
  - Cross Cloud Packages Solutions
release: "260"
---
# Sandbox Users with Non-Unique Usernames Can't Be Unfrozen

You can't unfreeze a sandbox user if their username exists in another sandbox instance. This change prevents duplicate usernames for active, unfrozen users. To unfreeze a user with a non-unique username, update the username to a unique value.

**Where:** This change applies to Lightning Experience and Salesforce Classic in all editions. This change applies only to sandbox orgs.

#### See Also

- [_Salesforce Help_: Freeze or Unfreeze User Accounts](https://help.salesforce.com/s/articleView?id=platform.users_freeze.htm&language=en_US)
- [_Salesforce Help_: Usernames and Passwords](https://help.salesforce.com/s/articleView?id=xcloud.basics_intro_usernames_passwords.htm&language=en_US)