Veeam - Defect ID: kb3130
Option to Install Veeam ONE Agent is Unavailable (Greyed Out)

Challenge

When attempting to install the Veeam ONE Agent on a Veeam Backup Server, the Install agent option is unavailable and greyed out.

Cause

There are several possible causes for this issue: The Veeam ONE Agent is already installed on the Veeam Backup & Replication Server. The Veeam ONE Server cannot communicate with the Veeam Backup & Replication Server. A Veeam ONE Agent is installed on the Veeam Backup & Replication server, but cannot communicate with that Veeam ONE Agent because port 2805 is inaccessible. The Veeam ONE Agent installed on the Veeam ONE Server is running in "Worker" mode.This may occur if the Veeam ONE Agent installer was run manually as its default install mode is Worker. The Veeam ONE Monitoring Service cannot communicate with the Veeam ONE Agent service running on the Veeam ONE server due to a misconfiguration.

Solution