Knowledgebase: KeyShot for ZBrush
Unable to Connect to External Renderer
Posted by Matthew Yetter, Last modified by Matthew Yetter on 05 April 2018 04:34 PM
When sending a model to KeyShot using the ZBrush to KeyShot Bridge you may receive an error that says "Unable to Connect to External Renderer."

There are several possible reasons why you may receive this warning:

If you have KeyShot 5 (the original KeyShot for ZBrush version) and never upgraded it, then upgrading to ZBrush 2018 (a free upgrade) will allow ZBrush to communicate with KeyShot 5 again.  Alternatively, you can visit My Licenses to see the costs of upgrading your KeyShot version.

If you have KeyShot 7.2, we have learned that there is an issue preventing ZBrush from launching it.  A solution is currently being looked for but until one is found there is a very simple workaround:  Launch KeyShot yourself, before starting ZBrush.  Once launched, KeyShot must remain open for your entire ZBrush session -- KeyShot may not be restarted while ZBrush is running or you will lose Bridge connectivity.  If you close KeyShot you will need to also restart ZBrush before you can use the Bridge again.

For all other versions:
  1. This is most likely because Live Linking is not activated in KeyShot. Go to KeyShot Preferences>Advanced tab, then click on Enabled Live Linking.
  2. The model may have been sent to KeyShot before KeyShot had finished launching. Try sending the model over again.