Authorization error: Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression

Symptoms

The error occurs when login and passowrd are entered: 

Exception Message: Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

Exception Type: System.Data.SqlClient.SqlException

Exception Source: .Net SqlClient Data Provider

Cause

The error might be caused by update.

Permission duplicates with equal positions.

Solution

Find the duplicate permission name (Code) via a request:

select SAO.Code, SAOG.Position, count(sao.id) from sysadminoperationgrantee SAOG
 
join SysAdminOperation SAO on SAO.ID = SAOG.SysAdminOperationId
 
join SysAdminUnit SAU on SAU.ID = SAOG.SysAdminUnitId
 
group by SAO.Code, SAOG.Position
 
having count(sao.id) > 1

After you find the name (e.g., "CanUseSharedMailBox"), find the list of record IDs that are duplicates.

SELECT * FROM SysAdminOperationGrantee WHERE SysAdminOperationId = (SELECT Id FROM SysAdminOperation WHERE Code = 'CanUseSharedMailBox')

After that, change the number of position in one of the records (does not matter which record). As a result, no duplicates will occur.

UPDATE SysAdminOperationGrantee SET Position = 1 WHERE Id = 'C3665747-F6F6-474F-8CEE-5A7678883F4B'