You can use the below command to open the symmetric key.

--Grant View
GRANT VIEW DEFINITION ON SYMMETRIC KEY::SQLSymmetricKey TO [UserName]

--Grant Control
GRANT CONTROL ON CERTIFICATE::SelfSignedCertificate TO [UserName]

• This reply was modified 4 years, 1 month ago by yash.viva93.

Thanks, Winston Smith.

It works for me.