There are hundreds of post on this topic but I just ran into this problem recently so I thought I should add one more. I created a package that sends a flat file to an FTP. The package runs fine in BIDS but when you deploy and try and run from a SQL Agent job it fails. Here’s a segment of the error:
Description: An error occurred in the requested FTP operation. Detailed error description: The password was not allowed . End Error
There’s actually a very simple solution to this problem. By default SSIS makes you package level encryption EncryptSensitiveWithUserKey. Some of the first posts I saw said to change encryption to DontSaveSensitive, but in testing I actually got a very similar error. The other option I saw was to try EncryptSensitiveWithPassword. Success! That did the trick.