​Microsoft is investigating a known issue that causes the new Outlook email client to crash when users click the "Go to classic Outlook" button, which should help them switch back to the classic Outlook.

"Some users have reported that the 'go back to classic Outlook' button in new Outlook for Windows does not open a support article on how to download classic Outlook for Windows," the company says in a Wednesday support document.

"The application just closes, and classic Outlook is not installed," as those clicking the button would expect.

While looking into the issue, Redmond also provides those affected with a temporary workaround, which requires them to install the classic client by clicking the store link in this support document.

Those who want to switch back can also download the standalone Outlook classic client for Windows or install it from the Microsoft Store.

If you're using a work or school account and can't install classic Outlook using any of the steps described above, you must reach out to your IT admin for assistance.

​Microsoft announced in December that the new Microsoft 365 desktop client app installed on Windows devices will also deploy the new Outlook in addition to the classic Outlook client. It also advised IT admins to edit their configurations and exclude the new Outlook app before new installations if it's not needed.

You can find more details on how to block users from connecting to new Outlook and controlling other features and capabilities like connecting personal accounts to the new client on Microsoft's support website.

Redmond also began force-installing the new email client on Windows 10 systems in January, starting with the KB5050081 non-security preview update. This move was first revealed in early January when the company said its new email client would be automatically installed for all Windows 10 users installing the February Windows security updates.

Last month, Microsoft fixed another known issue that broke email and calendar drag-and-drop in Outlook after installing recent updates on Windows 24H2 systems.

Since the beginning of the year, it has addressed other Outlook issues, including one that causes classic Outlook to crash when writing, replying to, or forwarding an email, and another one that led to Classic Outlook and Microsoft 365 applications crashes on Windows Server 2016 or Windows Server 2019 systems.