Inactive accounts have been pruned, users can now send invites once again.

Keep in mind the invite offering rules:

2.2. Do not trade, sell, publicly give away, or publicly offer invites. Only invite people you know and trust. Do not offer invites via other trackers, forums, social media, or other public locations. Responding to public invite requests is prohibited. Exception: Staff-designated recruiters may offer invites in approved locations.