This is an old problem that has returned. You belong to a group, you get a Notice with an attachment. You click the attachment expecting a Note Card or Landmark to open. But, nothing happens. If you’re lucky to can go to the group’s list of notices, open the notice, click the attachment, and have it work. Or maybe not.
I’ve been noticing this in SLViewers 2.? and up. The first report was with viewer 2.0.0. My current Second Life 2.8.3 (237297) has the problem. I suppose it could be the server. Whichever is the case the bug is reported as a viewer bug. See the JIRA item SVC-7129.
If you are having the problem, please drop by the JIRA and click Vote and Watch. If you don’t already know, the Lindens look at the Watch number. I am sure they do not completely ignore the Vote number. But, attention comes to those things with high a Watch number.