...
Make sure the user has enough permissions. You can use the 'Check Permissions' option on the SharePoint site that you want to crawl.
Failing to save a content source before creating or editing another content source can result in an error.
ERROR [aspire]: Exception received attempting to get execute component command com.searchtechnologies.aspire.services.AspireException: Unable to find content source
Save the initial content source before creating or working on another.