I am having a related issue as well... Not sure if it's the same, but I figure I'll put it out there.
When creating a new Calendar/Meeting invitation, I paste a document link (links to another notes database file) and send out the invitation.
Funny thing is, even though I (the meeting chair) can see the doclink, the recipients cannot. Their description on the meeting invitation appears blank.
Running Domino 9.0.1 and same for the clients.