Wordfence is the exception to almost everything else in this knowledgebase. Most plugins nag you for a license and work fine without one. Wordfence Premium genuinely will not run until a real Wordfence license is in place, and you get one from Wordfence, free, in about two minutes.
Do these steps in order. Installing Premium first is what causes most of the trouble.
1. Clear out any previous Premium install
If Wordfence Premium is already on the site, deactivate it, delete it, and choose to delete the database tables as well. Export your settings first if you want them back afterwards, and reimport once you are done.
2. Install the free Wordfence
Get it from Plugins → Add New Plugin in WordPress and search for Wordfence. Activate it.
3. Get your free Wordfence license
- Click Get Your WordPress License. That takes you to the Wordfence site.
- Choose Get a Free License.
- If a popup offers you a paid Firewall subscription, choose I’m OK waiting 30 days for protection from new threats.
- Enter your email address and submit. Wordfence emails you the license key.
4. Install the license
Back in WordPress, click Install an existing license, enter your email address, paste the key, and activate. A confirmation popup tells you the free license is in.
5. Install Wordfence Premium
Go to Plugins → Add New Plugin → Upload Plugin and upload the Wordfence Premium file from your account dashboard on 99plugs.com.
WordPress tells you the plugin is already installed. Click Replace current with uploaded. That is expected, and it is you swapping the free build for the premium one.
6. Set up your updates
Add your update key to the 99Plugs Update Manager so Premium keeps updating. See How to enable auto updates.
Why this one is different
Three kinds of activation prompt exist across the catalog and Wordfence is the rarest of them: a plugin that needs a genuine free license from the developer before the premium build will run. The other two are the common ones, and both come down to ignoring the prompt. My plugin or theme is not activating has the short table.