Yes. Simply enable both in the Settings page. It is totally fine to have both of them running at the same time.
Make sure you have the latest WordPress version running and have a modern web browser. If these are not a case, try cleaning browser's cache and cookies.
The same way you entered it the first time: Admin > Google Universal Analytics (below Settings button)
Check it out nexusAd tool.
Requires: 3.0 or higher
Compatible up to: 4.1.13
Last Updated: 2 years ago
Active Installs: 20,000+
Got something to say? Need help?