Polycom CX700 Exchange error

Some notifications of CX700 screen:

"Connection to Exchange is unavailable  due to invalid network credentials."

 in the Exchange log we see:

incorrect sequence:

2016-03-14 06:34:43 10.0.3.74 GET /autodiscover/autodiscover.xml - 443 - 10.0.3.14 OCPhone/4.0.7577.4066+(Microsoft+Lync+2010+Phone+Edition) 401 0 0 0

2016-03-14 06:34:43 10.0.3.74 POST /autodiscover/autodiscover.svc - 443 - 10.0.3.14 OCPhone/4.0.7577.4066+(Microsoft+Lync+2010+Phone+Edition) 401 0 0 0

2016-03-14 06:34:44 10.0.3.74 POST /autodiscover/autodiscover.svc - 443 - 10.0.3.14 OCPhone/4.0.7577.4066+(Microsoft+Lync+2010+Phone+Edition) 401 1 2148074254 0

2016-03-14 06:34:46 10.0.3.74 POST /autodiscover/autodiscover.svc - 443 - 10.0.3.14 OCPhone/4.0.7577.4066+(Microsoft+Lync+2010+Phone+Edition) 401 1 2148074254 0

correct sequence

2016-03-14 08:31:20 10.0.3.74 GET /autodiscover/autodiscover.xml - 443 - 10.0.3.14 OCPhone/4.0.7577.4066+(Microsoft+Lync+2010+Phone+Edition) 401 0 0 46

2016-03-14 08:31:20 10.0.3.74 POST /autodiscover/autodiscover.svc - 443 - 10.0.3.14 OCPhone/4.0.7577.4066+(Microsoft+Lync+2010+Phone+Edition) 401 1 2148074254 0

2016-03-14 08:31:20 10.0.3.74 POST /autodiscover/autodiscover.svc - 443 AD\user 10.0.3.14 OCPhone/4.0.7577.4066+(Microsoft+Lync+2010+Phone+Edition) 200 0 0 62

Seems to be password expire issue. As workaround we will reset user password or set password never expires.

here is a reference for other errors:

http://lyncuc.blogspot.ch/2013/01/lync-and-exchange-web-services-ews-and.html