On Google Chrome Canary Version 59.0.3062.0 (64-bit), with Norton Version 22.9.1.12 installed, the Norton Toolbar Extension 2017.0.0.8 loads when enabled and then immediately fails on both Windows 8 & Windows 10, giving this Error:
Uncaught Error: Invocation of form runtime.connect(null, ) doesn't match definition runtime.connect(optional string extensionId, optional object connectInfo)
Clicking "Repair" does not alleviate the problem, neither does manually removing and re-installing the extension. This is not present in the stable release of Google Chrome