"RTC_E_INVALID_OBJECT_STATE" error when you sign in Skype for Business 2015 (Lync 2013) Content provided by Microsoft Applies to: Skype for Business 2015Microsoft Lync 2013 Select Product Version All Products Symptoms You cannot sign in to the Microsoft Skype for Business 2015 (Lync 2013) client because of the RTC_E_INVALID_OBJECT_STATE error. Resolution To fix this issue, install the December 6, 2016, update (KB3127976) for Skype for Business 2015 (Lync 2013).Note Lync 2013 was upgraded to Skype for Business in April 2015. Last Updated: Dec 6, 2016 Did this solve your problem? Yes No Tell us what we can do to improve the article Submit Thanks! Your feedback will help us improve the support experience.