Hi Bert
Are you using the latest version of Enterprise Manager solution avaialble at https://www.outsystems.com/NetworkSolutions/ProjectDetail.aspx?ProjectId=64?
This version was updated to be supported by Agile Platform 5.0.
A new version of the StyleGuide is also available at https://www.outsystems.com/NetworkSolutions/ProjectDetail.aspx?ProjectId=6.
You should publish the EnterpriseManager solution prior to publishing the OutSystems Styleguide.
Cheers
Miguel Simões João