I have an SSIS package with a valid and tested rest connection and a REST source that uses the REST connection that can successfully preview the data being selected. However, when I attempt to run the package, the REST source fails validation with this error:
“Required. Specify client identifier”.
If you choose to use the option DontSaveSensitive, all sensitive information like passwords and other credentials are completely removed from the package. This option can only be used if you provide your passwords from an external configuration file or a table.
We recommend that you use EncryptSensitiveWithPassword. If you want to set up package encryption with either EncryptAllWithPassword or EncryptSensitiveWithPassword, be sure to include the package decryption parameter. There is an example here how to set the /DECRYPT option with password here and information about the DTEXEC command line options is available here.
Please change your package protection level and then try to run the package again.
You may find the following articles useful: