Error: "Resource is unavailable" when trying to apply a CA template to a policy object

Symptom:

While applying a CA Template to a policy object...

This error is shown:

Resource is Unavailable: The resource you have requested is unavailable due to an exception. Click OK to go back.

This issue is caused by a known issue with Venafi Encryption Director version 6.0.1

Resolution:

A Field Test Patch is available that resolves this issue. Please contact Venafi Support to get access to the patch.