I have tried to share my Live.com / Outlook calendar with a google account I own but I get the following error:

"Sorry, this invitation isn't valid anymore. The sender may have taken away your permission, or you may have already declined this invitation. If you'd like to see this calendar, ask its owner to share it with you again."

Since I am both the sender and the recipient this makes no sense.   I have also tried to re-send, paste the accept link and use via links, all to no avail.

Please advise.

Thanks.