This reply was originally posted by Bill on APC forums on 3/30/2016
Verify that the PowerChute Server is using the same user name and password and the PowerChute Agent. When installing the PowerChute Agent you are required to enter a user name and password. The when installing the PowerChute Server you are again asked to enter a user name and password. If those do not match the PowerChute Server will not discover the Agent.
You can change the user name and password for the PowerChute Server in the Console. Go to Tools - Change User Name/password
If the Agent is displayed in the console with UPS Communication Lost and you can access the Agent via the web interface and it show communicating with the UPS you should
1 - In the Console go to Tools - Configuration Device List and remove the Agent and click apply. Then re-add the Agent and click apply.
2 - If step 1 does not resolve the issue stop and the restart the Agent service. Open a command prompt as an administrator and enter net stop apcpbeagent. After the service stops restart it. The command is net start apcpbeagent.