Such problem appears due to insufficient privileges assigned to the user under which HCRemoting Service is running on the Lync 2010/2013 Server.
Recommendation is to run HC Remoting Service under Domain\Administrator account. You can access Services MMC from : Start >> run >> services.msc .
Trouble logging in? Simply enter your email address OR username in order to reset your password.
For faster and more reliable delivery, add firstname.lastname@example.org to your trusted senders list in your email software.