Why can't I message or see someone?

Usually: consent, working as designed

• No Message button? You can message connections and candidates who accepted your outreach — no one else. That's the consent model, not a bug.
• Outreach unavailable? The member has turned recruiter outreach off, or caps are in effect.
• A profile looks thinner than expected? Members control what's public — timeline entries, leaderboard presence, and more are all optional.

Possibly an actual problem

If a conversation you definitely had has vanished, or a connection shows on one side but not the other, that's worth a report — open a ticket with both profile links and roughly when you noticed.