Add a new temp watch extension target and check the complication check box. Copy the complication extension properties from this new info.plist (CLKComplicationSupportedFamilies, WKExtensionDelegateClassName & CLKComplicationPrincipalClass) into your old watch extension info.plist. Once you do that you will see the complication Families listing.
I also moved the ExtensionDelegate & ComplicationController classes into the old watch extension and changed the target membership to the old watch extension from the new watch extension.
Right click inside the old watch extension asset file and add the complication image set.
Also "tom_witkin
Jul 23, 2015 8:50 AM
(in response to breville)
The ClockKit framework is only available on watchOS 2, not iOS. Thus, complications are not supported for existing WatchKit apps where the extension is running on the iPhone."
So do the recommended build settings change when moving from wos1 to wos2 (if there is a warning during compilation), and make WATCHOS_DEPLOYMENT_TARGET = 2.0 in both the old extension & watch app build settings.
Add TARGETED_DEVICE_FAMILY = 4 for old watch extension, if not present.