Mobile Advert is meant to be used in exported mobile applications only.
Remove it completely from your project for an HTML5 export.
it is tricky to remove it, it can break a lot of things. if to make separated apps, it is also hard, because you will need to make all updates in the 2 apps that potentially can be (and will be) a reason of bugs
not easier to just ignore it?
By the way, I tried to separate the code by means of platform info plugin, but it is not working, because html5 on android is classified as "on android" and not as a web export. I believe android got to be only for native android app. probably the same things on iOs