LinkedIn profiles can get restricted for many reasons, but here are a list of a few:
- The profile is manually flagged by several people on LinkedIn as spam.
- Too many outstanding pending invites (but usually this leads to not being able to send invites not a profile restriction)
- Sending too many invites in a given 24hr timeframe (we recommend 50-100 invites per day, even if you are using a paid version of LinkedIn).