EcoStruxure OPC UA Server Expert v2.01 uses Windows CA certificate based on DNS and Windows does not permit computer names that exceed 15 characters for DNS and NETBIOS host name.
So, the maximum number of characters for a computer name using EcoStruxure OPC UA Server Expert is 15, otherwise Windows truncates the DNS Name for 15 characters with a different  domain name and EcoStruxure OPC UA Server Expert returns the message below.

Released for: Schneider Electric Global