Symptoms
Assume that you have several undocked conversation windows (free-floating windows that don't appear as tabs in the tabbed conversation window) with different widths and heights, and you check the Reopen my conversations when I sign in option in the General section in the Options dialog box in Microsoft Skype for Business 2015 (Lync 2013). After you sign out, and then sign back in Skype for Business 2015 (Lync 2013), those conversation windows are restored, and they are all restored by using the same width and height.
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.
