There are many people around the web who have had this problem it seems.
When I visited https://static.doubleclick.net/robots.txt I see that it is blocking all bots from crawling its content. This means that fetch and render should not be able to crawl it for anyone using doubleclick and so there should be no cause for alarm. Googlebot understands what doubleclick is of course.
On the other hand, this error seems somewhat unusual, but others have had it. One person said his site started deranking after receiving tens of thousands of these errors on his site from the same issue you're having regarding doubleclick.
The severity of this error is reported to you as "Low" which should indicate that it's not much of a concern.
Ultimately, I think that it's possible that Google is reporting this as an error to you because an error on its own end. Whether or not this could effect the indexing of your page or ranking of your site I'm unsure of as there doesn't seem to be that much information out there on this issue.
You may want to consider removing the doubleclick code from that specific page if possible to prevent this error from continuing.
Here are some related posts in the Google forums that may give you some more information: