Use ActiveX controls for Internet Explorer 11 - Microsoft Support
Learn how to use and customize ActiveX controls and filtering in Internet Explorer.
Enable ActiveX controls in Internet Explorer - Microsoft Support
To run Lync Web App in Internet Explorer, you must enable ActiveX controls. Click Tools > Internet Options. Click the Security tab > Custom Level. Click OK to close the dialog boxes, and then restart Internet Explorer. For Internet Explorer 9 and later, you must also disable ActiveXFiltering, if turned on.
Applies To:
Lync Web App for Lync Online, Lync Web App, Lync Web App operated by 21Vianet
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