Symptoms
Assume that you create a topic feed in Microsoft Skype for Business 2015 (Lync 2013). When you clear the input text or click the input area in a room filter dialog box, the Close button doesn't reset the results.
Resolution
To fix this issue, install the January 3, 2017, update (KB3141468) for Skype for Business. Note Lync 2013 was upgraded to Skype for Business in April 2015.