The Business Connector proxy account might not have the appropriate permissions on the server to allow access. The Business Connector proxy must:
- Be a user in Active Directory.
- Be a member of the Power Users, IIS_WPG, STS_WPG, and the Performance Monitor Windows groups on the server that runs IIS and hosts Enterprise Portal
Create a user with domain in active directory
Also in administrative too you can find above list of members in user in that properties add the member tab Domain / user that you created as business connector proxy