You may receive this error when creating or updating a user account:
Violation of UNIQUE KEY constraint 'IX_Users'. Cannot insert duplicate key in object 'Security.Users'. The duplicate key value is ([email protected]).
This means the email address you are trying to use already exists in the Security.Users table. Each user must have a unique email address, so the system will block the creation of a new account if the email is already linked to another user.
To resolve this, first check the existing users for someone with the same name. If it is the same person (for example, a rejoiner), you can simply reactivate the existing account, as long as it is attached to the same person record.
If it is a new person but the system is assigning the same username because they share an email address, you will need to create the user manually in the admin tool.
You can do this either by changing the username on the old account or by giving the new user a different username.