Thanks Umberto,
Yes, I have activated them and inserted the license keys. I can load the airports and get the 'Airport cache loaded successfully' message. All other systems -boarding, deboarding, catering, fuel loading etc., operate successfully but no jetways.
I've noticed on Add-On Manager that the SODE version is 1.6.3. Should I update to v1.6.8?
Also, at CYVR I can't get the proper gate designations. They're all listed as 'Ramp GA' or 'Ramp Cargo GA'.