Unclosable Ads

Whenever an ad for a certain pre-registration app pops up, I can never close it. Has anyone else experienced this...? Are there any workarounds? For reference, only the bottom banner-like part appears, and the main part (presumably where videos play) is black, so I suspect it's not loading properly. Up until now, even ads that didn't load properly could be closed, so not being able to close them is really stressful~ (crying)