CRM 2013: Data Encryption error

Microsoft Dynamics CRM 2013 uses standard SQL Server cell level encryption for a set of default entity attributes that contain sensitive information, such as user names and email passwords.

when you try to update user email in user entity you will get the following error:

when you open log file you see the error details "Cannot open Sql Encryption Symmetric Key because Symmetric Key password does not exist in Config DB."

To solve this problem (CRM on premises) :

1- Open SQL server management tool and form CRM database select new query the write the following script:

SELECT [ColumnName],[BitColumn]

FROM [MSCRM_CONFIG].[dbo].[DeploymentProperties]

WHERE ColumnName='DisableSSLCheckForEncryption'

UPDATE [MSCRM_CONFIG].[dbo].[DeploymentProperties]

SET [BitColumn]=1

WHERE ColumnName='DisableSSLCheckForEncryption'

After performing an IISReset on the CRM Server, you’ll be able to see the encryption screen.  Paste the encryption key in to a "CRM > Settings > Data Management > Data Encryption" screen, such as Notepad then click change. As a best practice, save the text file that contains the encryption key on a computer in a secure location on an encrypted hard drive

(if data Encryption status is inactive and current encryption key is null you can use guideGen.exe to generate key then past the the encryption key into "CRM > Settings > Data Management > Data Encryption" screen then click Activate)