Unable to start execution of step 1 (reason: Error authenticating proxy DOMAIN\USER, system error: ConnGetProxyPassword). The step failed.
I encountered this error when running a Job. The error occurred when the SSIS package in Job was run with a Proxy. The proxy account is also using a Credential, and the problem was due to an incorrect password definition for the user in the Credential definition.
Make sure that the appropriate Credential settings are correct. Make sure that the user information you are using is correct.