I have invocation tags on my website but no ads are displaying. Why?

There are many possible reasons why ads are not being displayed as expected. We've listed the common issues in this FAQ entry. Please review these before posting your question on the forum:

1. Check that the ad tag you are using will work with the banners you've linked it to. We recommend Javascript tags. If you are using an image tag you will only be able to serve image banners. In the case of Local Mode or XML-RPC tags, it would be a good idea to do a test using a Javascript tag to help ascertain whether the issue is related to how you have set up your Local Mode or XML-RPC tag or delivery (setting up these tags is quite technical).
2. Double check that you have active banners linked to the zone: go to zone properties and look at the Linked Banners tab and the Probability tab. (For advanced users using Direct Selection, make sure that you have active banners in your inventory which match the Selection String.)
3. Have you recently upgraded OpenX or changed your server setup? Try generating new invocation tags inside OpenX and see if these work. If your old tags don't work but the new ones do:
   • Perhaps you placed the new OpenX files in a different folder on your server. Your old invocation tags would be pointing at the old folder. You either need to generate new tags, edit your old tags to use the correct folder name, or move OpenX back to the folder it used to be in.

   • Did the domain name you use change? Similar to above, the old tag would be using the old domain.
   • Have you recently changed MySQL settings in any way? OpenX might not be able to correctly connect to MySQL and you will need to review the database settings in your configuration file at openx/var/www.yourwebsite.com.conf.php
   • When upgrading or moving your files, did you copy the banner images from your images directory? In 2.4, the default image directory is openx/www/images. Your images might be contained in a different folder if you have modified this default setting.
4. Check that the problem is repeatable on different web browsers and computers. You may have ad blocking software which is preventing the banner from being delivered.
5. If you have changed what banners are linked to the zone, there is a delivery cache time before changes become viewable - the default is 20 minutes.
6. Do you have a banner linked to the zone which is in a low-priority non-limited campaign? If you have banners which have session-capping enabled your session might have already viewed all possible banners, and now OpenX has nothing to display. Make sure a non-limited banner is linked to the zone so that a banner is always delivered. You could delete your cookies if you think this might be the issue.