Ads link to error pages
When you link Analytics and AdWords, destination URL auto-tagging is turned on automatically. This feature allows Analytics to track information about clicks on your AdWords ads by tagging your AdWords keyword destination URLs with a gclid= parameter. This parameter is displayed in your landing page URL.
A small number of websites don't allow URL parameters, and consequently serve an error 404 page when a URL contains those parameters. If your site doesn't allow URL parameters, you can lobby your webmaster to allow them, or you can turn off auto-tagging.
To turn off auto-tagging:
- Sign in to your AdWords account at https://adwords.google.com.
- Click the gear icon, and select Account settings.
- Make sure you're on the Preferences tab, and click Edit in the Tracking section.
- Clear (disable) the Destination URL Auto-tagging checkbox.
- Click the Save changes button.