SSL Server Verification is enabled by default. If you receive an error such as "Error: verify is enabled by default but no CA file specified" you can disable verification by navigating to
Balancer -> Configuration -> Default Settings -> Group Defaults and Change SSL Server Verify to "None"
or you can set it by single group by navigating to
Balancer -> Group/Frontend Management -> Edit -> SSL Options and then selecting the Client Certificates as "None"