S4U licensing issue

I have downloaded (via the extension warehouse) and paid the $5 license fee (via the extension warehouse) for the S4U extension, yet it still shows as unlicensed.

I have already tried uninstalling, restarting SU and reinstalling the extension, but it still shows as unlicensed. I have the receipt for my payment in my email so I know payment has been made.

Does anyone know how to get extension licensing to work?

I expect you’ll get an e-mail from the author with the license info. It may have come and got sorted into your spam box so check there.

No, sadly not, it was purchased over a month ago and I only have the email confirmation of my purchase. On the Extension Warehouse page for this plugin the comments show quite a few people have had this licensing issue and the author is directing us to Sketchup for assistance.