Hi Tony,
Since you said you encounter the different situation from Nat, I would like to confirm more other information:
1. Do you also use Lync for Mac?
2.If not, can you sign in to Lync for windows before?
In addition, according to the error message “the server cannot be reached to validate you password. Make sure your computer is connected to the internet”, this issue may occur because a proxy firewall blocks HTTP port 80. Therefore, Microsoft Online Identity service (Msoidsvc) cannot connect to the Microsoft Online Live ID service to validate the authentication.
To work around this issue, we can use one of the following methods:
1. Unblock port 80 outgoing on the network edge or proxy edge.
2. Manually configure the WinHTTP proxy by using a valid proxy setting.
Thanks,
April Zhou
Since you said you encounter the different situation from Nat, I would like to confirm more other information:
1. Do you also use Lync for Mac?
2.If not, can you sign in to Lync for windows before?
In addition, according to the error message “the server cannot be reached to validate you password. Make sure your computer is connected to the internet”, this issue may occur because a proxy firewall blocks HTTP port 80. Therefore, Microsoft Online Identity service (Msoidsvc) cannot connect to the Microsoft Online Live ID service to validate the authentication.
To work around this issue, we can use one of the following methods:
1. Unblock port 80 outgoing on the network edge or proxy edge.
2. Manually configure the WinHTTP proxy by using a valid proxy setting.
Thanks,
April Zhou