Article ID: 2701556 - View products that this article applies to.
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Am I using Office 365 after the service upgrade?
You install Microsoft Office Professional Plus 2013 on a computer that has Microsoft Lync 2010 installed on it. However, when you try to sign in to Microsoft Lync Online with Lync 2010, you can no longer sign in.
To work around this issue, follow these steps:
This is a known issue in side-by-side installations of Lync 2013 and Lync 2010. This occurs if the Microsoft Online Services Sign In Assistant wasn't installed on the computer before you installed Office Professional Plus 2013.
Still need help? Go to the Office 365 Community