IIS 6.0 No Sites or 'the path specified cannot be used at this time'

If your IIS Manager on a SharePoint server is failing to load the websites for the server, your SharePoint Timer Service may be trying to access IIS 6.0 at the same time (multiple threads).

Microsoft released a hotfix back in January to resolve this issue.

Unable to manage IIS: https://support.microsoft.com/?id=946517