On network settings page/Main Account when you try to authorize a facebook or linkedin account, callback URLs are /wp-admin/options-general.php?page=NextScripts_SNAP.php instead of wp-admin/network/admin.php?page=NextScripts_SNAP.php so the authorization does not work and you will get: “You do not have sufficient permissions to access this page.”.

I ended up manually editing the URLs on each request to successfully authorize the accounts.