@Nikki reports that the Structured Data on Commons user interface does not work on Internet Explorer 11 – clicking on the “structured data” tab does nothing. In the console, an error appears:
SCRIPT5007: Object.getPrototypeOf: 'this' ist kein Objekt [translation: 'this' is not an object]
I assume this is because, according to MDN,
In ES5, it will throw a TypeError exception if the obj parameter isn't an object. In ES2015, the parameter will be coerced to an Object.
And WikibaseMediaInfo contains code like this:
Object.getPrototypeOf( d[ key ] || '' ) === Object.prototype
which directly relies on Object.getPrototypeOf( '' ) being valid, even though apparently in ES5 it’s not.