Page does not Appear Correctly
You may not see a preview for a page if it requires a login. In this case, you can follow the login request in the preview window, or load the page in another browser tab and follow the login request there. After you have logged in, refresh the preview window by clicking either the back or forward button at the top of the preview window, and then return to the page in question.
Added Parameters not Allowed by Web Server
Content Experiments adds parameters to the URL when it redirects from the original page to one of the variations:
utm_expidis added to include the experiment ID in the URL
utm_referreris added when there is a referrer to the original page
The addition of these parameters can make your variation pages unavailable if your web server does not allow unknown URL parameters. To ensure that your variation pages are available both in the wizard during setup and to your users when the experiment is running, add these two parameters to your web servers's list of approved parameters.
If your web server does not allow these parameters, your variation pages may not be displayed in the previews in Step 2 of the wizard, and/or your validations in Step 4 may fail. In addition, the variation pages may not be available to users who are included in an experiment, which would cause them to see page-unavailable errors.