Summary: How to update Rhino 5 to get the most recent fixes.
Related installation help: Troubleshooting Rhino 5 Installation
How do I get a Service Release?
The quick way is to use the Check for Updates service. In Rhino, pull down the Help menu, and pick Check for Updates. If you are connected to the internet, the McNeel web servers will offer the correct Service Release if there is one newer than your software. For Flamingo, pull down the Raytrace or Photometric menu and pick Check for Updates. For Bongo, pull down the Bongo menu and pick Check for Updates.
In Rhino 5, go to Tools, Options, Updates and Service Releases and set the frequency to Service Releases or if you are brave, try Release Candidates. When you close Rhino, it will prompt you to approve the install of the latest and greatest. You may decline and run it after a future session.