As of 17th August 2021, Internet Explorer 11 is no longer supported as a valid browser for accessing Microsoft 365 apps.
If you are still running Windows 7 and Internet Explorer you should, in the first instance, contact the ICT Service Desk to enquire about an upgrade to Windows 10. ICT can advise appropriately on use of Windows 7 as an operating system where there is an operationally insurmountable reason for continuing to run Windows 7.
Unless there is an absolute reason for running Windows 7 (lab equipment / microscope / imaging applications that cannot be upgraded), all systems should be upgraded to Windows 10.
If you need to access Microsoft 365 applications from a machine where you were using Internet Explorer 11, please install the latest version of Google Chrome or Microsoft Edge and use those instead.