Unable to Connect to External Renderer

Matthew Yetter
Matthew Yetter
  • Updated

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.

For all other versions:

  1. The most common cause of this issue is that antivirus software created issues during installation of ZBrush.  Please uninstall ZBrush, delete its folder, then disable all antivirus software (including Windows Defender) prior to installing again.  This resolves the problem for about 80% of users.
    • Please note:  We recommend a FULL reinstall for this.  That means that you need to not only delete the ZBrush folder itself but also the appropriate ZBrushData folder (such as ZBrushData2020).  For Windows users that folder is found in C:\Users\Public\Public Documents.  For macOS users it is in /Users/Shared.
  2. The next most likely because Live Linking is not activated in KeyShot. Go to KeyShot Preferences>Advanced tab, then click on Enabled Live Linking.
  3. Finally, the model may have been sent to KeyShot before KeyShot had finished launching. Try sending the model over again.




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