The giant from Redmond is forcing IT admins using Internet Explorer 11 to move to its Chromium-based Edge browser as soon as possible.

Microsoft this week announced a cut-off date after which Office 365 apps and Teams will no longer work with its legacy browsers. That means admins relying on Internet Explorer 11 or the old Microsoft Edge will need to move to the new Chromium-based Edge browser.

According to Microsoft, as of August 17, 2021, those who still use the old Edge browser or IE 11 can expect a “degraded experience”. In some cases, they may not even be able to connect to Microsoft (Office) 365 apps on IE 11 anymore. 

Ensuring a “smooth transition”

Microsoft made the announcement in a blog post on Monday. In th epost, they explain what they mean by “degraded” experiences.

“For degraded experiences, new Microsoft 365 features will not be available or certain features may cease to work when accessing the app or service via IE 11,” they explain. “While we know this change will be difficult for some customers,” they say, “we believe that customers will get the most out of Microsoft 365 when using the new Microsoft Edge.”

“We are committed to helping make this transition as smooth as possible,” they assure us.

Part of that commitment, according to the company, is respecting the investments that enterprises have made in Internet Explorer 11. “We understand the need to “do more with less” in the new business environment,” they say. “By the dates listed above, customers should no longer access Microsoft 365 apps and services using IE 11, but we want to be clear that IE 11 isn’t going away.”

Moreover, Microsoft claims that their customers’ own legacy IE 11 apps and investments will continue to work. “Customers have made business-critical investments in IE 11 legacy apps,” they wrote, “and we respect that those apps are still functioning.”

Dumping Edge “Legacy” for the “New Microsoft Edge”

Microsoft is also ending support for the Microsoft Edge Legacy desktop app on March 9, 2021. This means that users will get no more security updates after that date. The company is planning to release a Windows 10 mandatory update on April 13, 2021. That update will include the new Chromium based Microsoft Edge.

“Apps and sites created for Microsoft Edge Legacy will continue to work in the new Microsoft Edge,” Microsoft assures us, “but if a compatibility issue does arise, we have our App Assure promise to provide support.”