If you have installed the Chameleon code snippet and then use the Chrome Extension to switch to Test Mode, and see the following error: "No user identified"
This means that you are not correctly sending a unique user ID for each individual user. This is a core requirement for Chameleon to function and is how Chameleon tracks which Experiences to show which users.
Learn how to do fix that here:
Note: if you have installed Chameleon through Segment.com then you will need to ensure that you are identifying individual users to Segment. Documentation on how to do that is on Segment's website here, and best practices around this here.