This article will show you how to solve common pre-population issues, please note the first section of this article only applies to Eloqua. 

So, the gate script is present and rendering as it should, but there is no pre-population occurring.
There are two types of pre-pop used by to ensure the best user experience. If the forms are not pre-populating, it is important to know which method is not working.

The first thing to do is check that the Eloqua tracking script is on the page.

From Marketing Automation Platform (MAP) 
In the case of Eloqua, you can verify if Eloqua is script is running properly: 

Open the console > type _elq directly into the console (not the search or filter) and hit enter > do the same for _elqQ > check for error messages. 

If you see a red error message like the one below, then the Eloqua tracking script is missing and it needs to be added in.

If the script is on the page you should see a message like this one below. 

Additionally, along side the Eloqua tracking script the current user's Cookie ID must be known for pre-pop to occur.  

Built in Browser Cache
This layer means that every time a form is submitted, a snap shot of the submission data is stored in an encrypted storage key within the browser. 

This is done so we can pre-pop subsequent forms without having to rely on the Eloqua contact records being up to date or known. Occasionally, this caching layer can affect of testing MAP pre-pop and you may need to clear this layer. 

To clear the browser storage: 

Open developer tools > goto applications > expand local storage > click on the child item that matches the domain of the current page > locate GCDCApp > delete it the key using the big X > repeat for the same key in session storage > finally hard refresh the page. 

You can hard refresh by right clicking the refresh button while the developer tools window is open.

If you have followed these steps it means that any pre-pop data at this point must be coming from the MAP. 

If you are still having issues, fear not, is on hand, simply click "+ New Support Ticket" above.