On a server running SQL 2014 SSIS with SSISDB configured, one of the SQL Agent jobs configured to run using a proxy account kept failing with the error below.
Unable to start execution of step 1 (reason: JobOwner domain\domainuser
doesn‘t have permissions to use proxy 1 for subsystem SSIS). The step failed.
Solution that worked for me in my situation.
Query your proxys and see if that proxy is disabled. If so, enable it.
SELECT * FROM msdb.dbo.sysproxies
USE msdb ;
@proxy_name = ‘MyProxyUSerUser’,
@enabled = 1;