Microsoft has been planning to end support for its Internet Explorer browser since 2015, when it introduced its Edge browser. That support for IE from Microsoft will end in August, 2021. Read more here
But even today, IE is not appropriately configured to handle most modern websites. And that now includes Educa. Recent innovations added to the Educa site - to help improve speed and reliability - rely on browser tools and capabilities that are not available in the IE browser.
And so if you are using IE, for a better experience on Educa, please update to Chromium-based Edge, Chrome or Safari.
Note, the Educa web on an iOS device requires using Safari.