Following WPMUDEV Blog Comments Fails


I commented on a WPMUDEV post and clicked the follow option.

I received an email asking me to subscribe to the commets on the blog:

Hey there!

You recently followed one of our posts. Awesome! From now on we'll let you know when new comments are posted.

To activate, click "Confirm Follow" below.

Blog Name: WPMU DEV Blog
Blog URL:

However, when I clicked FOLLOW I encountered a message that the subscription could not be activated.

I am confused.