Membership Pro 2 activated but not working

Hi. I have installed the plugin and it seems to work. However when I browse a protected page without being logged in I get the following message:

[ms-protection-message]

I figured it is because the protection message is not set but I believe it is set.

Any idea why I am getting that message?

btw: The protected page is called "Gallery Test" and I have already granted you access in my dashboard.

Thanks