This error message appeared the other day and it turned out it wasn’t as bad as it looked.
Failed to decrypt protected XML node “DTS:Password” with error 0x8009000B “Key not valid for use in specified state.”. You may not be authorized to access this information. This error occurs when there is a cryptographic error. Verify that the correct key is available.
The protection level is set to EncryptSensitiveWithUserKey on the package and the account password used to access the source database was changed. Once the password was modified in the package everything ran as expected.