Governance Engine requires that you configure Salesforce to use OAuth for provisioning. See Configure OAuth and REST integration.
Only users with the profile entitlement can be assigned to Salesforce. A best practice to avoid assignment failures is to include the profile entitlement in commonly assigned bundles. This ensures that every user assigned to Salesforce has the required entitlement.
When you enable provisioning for Salesforce, follow the directions in Enable Salesforce provisioning