If some Outlook on the web features are not working properly because you are using an unsupported browser, you can switch to Outlook on the web light version. First, select Settings in the cogwheel menu  (upper right), then check light version as in picture below and click on Save. Next time when you login to Outlook on the web, you will be using the light version. If the view has not changed yet, log out, delete the browser cache and then login again.

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