Error when fetching GADUnifiedNativeAd using GADAdLoader

[grd888]

Running the sample app NativeAdvancedTableViewExample, I get the following error upon submitting the adLoader.load(GADRequest()) line.

In the adLoader(_,didFailToReceiveAdWithError),

Google:HTML undefined is not an object (evaluating 'a.tracking_urls_and_actions')
<GADAdLoader: 0x6000000b98c0> failed with error: Request Error: Received invalid response.