Display problems sometimes occur in the Visual Experience Composer (VEC) and the Enhanced Experience Composer (EEC) under certain conditions.
The EEC is an extension of the VEC that helps you edit an experience for an iframe-busting site or pages that do not yet include the Target implementation. If you have trouble opening your page in the VEC, try the EEC.
For information about the VEC and the EEC, see Experiences.
The following issues are common to both the VEC and to the EEC:
The following issues are specific the VEC only:
The following issues are specific to the EEC only:
This can happen if the URL contains a # character. To fix the issue, switch into Browse mode in the Visual Experience Composer, and then switch back to Compose mode. The spinner should go away and the page should load.
If your website's CSP headers block Target libraries, then loads the website but prevents editing, ensure that the Target libraries are not blocked.
As a workaround, you can configure a Requestly rule to remove CSP headers, as shown below:
You can configure a similar Requestly rule for any header that causes a resource to not load inside the VEC.
If the website has changed outside of the Visual Experience Composer after the experience was defined, selectors on which actions were taken earlier cannot be found when the activity is opened for re-editing. The page appears broken, and no warning displays.
This issue happens when customers have an mbox.js version earlier than 57 (i.e. version 56 or earlier).
If the same DOM element ID is used on multiple elements on the page, changing one of those elements changes all elements with that ID. To prevent this from happening, an ID should be used only once on each page. This is a standard HTML best practice. For more information, see Page Modification Scenarios.
This issue can be addressed by enabling the Enhanced Experience Composer. Click Setup > Preferences, then select the check box that enables the Enhanced Experience Composer. The Enhanced Experience Composer uses an Adobe-managed proxy to load your page for editing. This allows editing on iFrame-busting sites and allows editing on sites and pages where you have not yet added Adobe Target code. The activities do not deliver to the site until the code has been added. Some sites may not load via the Enhanced Experience Composer, in which case you can uncheck this option to load the Visual Experience Composer via an iFrame. 
See "I can't edit experiences for an iFrame-bursting site" above.
If you use Edit Text/HTML in the Visual Experience Composer for A/B or Experience Targeting activities or Change Text/HTML for Automated Personalization or Multivariate Test activities to make text bold or italic, those styles might not be applied on the page or the text disappears from the page in the Visual Experience Composer. This is because the way the rich-text editor applies these styles might interfere with the website markup.
If you see this issue:
Adding an image offer to a location takes the full dimension of the original image space in the VEC or EEC. On delivery, the image is not expanded and is shown as it is, so there is no impact on delivery.
Target adds two parameters (mboxEdit=1 and mboxDisable=1) while opening the website in the Visual Experience Composer.
If your website (specially Single Page Apps), trims our parameters or actually removes them while navigating from one page to another (without a page reload) the Target functionality breaks and the Target libraries do not load.To avoid this problem, ensure that you do not trim or remove these two parameters.
Several issues can affect page performance in the Target experience composers. Some common issues include:
If issues occur in the Enhanced Experience Composer, try turning off the Enhanced Experience Composer and use the Visual Experience Composer instead.
To disable the Enhanced Experience Composer, go to Setup > Preferences and turn off the Enable Enhanced Experience Composer option.
Some users see the following error message in the console:
If neither the Visual Experience Composer nor the Enhanced Experience Composer works, use a browser extension like Requestly (Chrome or Firefox) or Modify Response Headers (Firefox) that can overwrite the X-Frames header options for your site and allow them to be loaded in iFrames, enabling the VEC. If you are unable to use browser extensions, use the Form Composer.
To use the Requestly extension on Chrome or Firefox:
Turn off the Enhanced Experienced Composer.
Install the Requestly browser extension on Chrome or Firefox.
Open the extension and configure it using the following:
Select Modify headers.
Enter the following:
Toggle Add to Remove.
Toggle Request to Response.
Enter "X-Frame-Options" as the header name.
Repeat previous steps and enter "x-frame-options" as the header name.
Change Equals to Contains as the condition for the source URL and enter the URL of the activity that you are trying to load in the VEC.
You should now be able to load the page quickly with the Visual Experience Composer.
To use the Modify Response Headers extension on Firefox:
Install the Modify Response Headers on Firefox and restart the browser.
From your Firefox extensions, select the Modify Response Headers extension.
Select Filter from the Action drop down.
In the Header Name field, enter: X-Frame-Options.
Repeat Steps 4 and 5 to add a filter with x-frame-options.
After setting up an extension, open Target. Your pages should now load in the Visual Experience Composer, even if the Enhanced Experience Composer is disabled.
Click the icon to the left of the URL in the browser address bar and click Disable protection on this page
This error occurs if you try to deliver Visual Experience Composer (VEC) campaigns and you have not updated mbox.js downloaded from the Target user interface with the Support Visual Experience Composer Activities option enabled (Setup > Implementation > mbox.js > Edit mbox.js Settings).
Ensure that this setting is enabled, then download and update mbox.js on your website.
While using browse mode, if you access a URL that does not have target.js or contains a frame-buster header, the Visual Experience Composer appears broken. Due to browser security concerns, Target cannot access the URL you navigated to.
This can be resolved by whitelisting the following IP addresses. These IP addresses are for Adobe's server used for the Enhanced Experience Composer proxy. They are only required for activity editing. Visitors to your site do not need these IP addresses whitelisted.
Europe, Middle East, and Africa (EMEA)
You might see the following error message in Target:
Error: Your website domain (ISP) is blocking the Enhanced Experience Composer. You can whitelist the Enhanced Experience Composer's IP addresses or turn off Enhanced Experience Composer in Configure > Page Delivery menu.
The following are reasons that you might see this error message and remedies to fix the situation:
Issue: Your website domain (ISP) is blocking the Enhanced Experience Composer.
Remedy: Whitelist the IP addresses listed above.
Issue: The IP addresses are whitelisted but your website does not support TLS version 1.0. Target currently uses the default configuration of 1.0.
Solution: See the following question (The Enhanced Visual Experience Composer won't load on secure pages on my site that use TLS 1.2).
You might see the error message described above in "The Enhanced Visual Experience Composer won't load on secure pages on my site." if the above IP addresses are whitelisted but your website does not support TLS version 1.0. Target currently uses the default configuration of 1.0.
To check the TLS version on your website using Firefox (other browsers have similar steps):
Open the affected website in Firefox.
Click the Show Site Information icon on the browser's address bar.
Click Show Connection Details > More Information.
Examine the TLS version information under Technical Details:
To remedy this situation, reach out to Customer Care for configuration with your TLS version and the domain.
Make sure proxy IPs are not blocked in your environment.