"This operation requires a connection to the
'master' database. Unable to create a connection to the 'master' database
because the original database connection has been opened and credentials have
been removed from the connection string. Supply an unopened connection."
I had this error and solved it by adding "Persist
Security Info=true" to the connection string.
意思是在连接字符串上要加 Persist Security Info=true
Persist Security Info=true
只是不明白 为什么在出现一次错误后 第二次就不会出现 难道出现过错误