When you set up Tekla Structures license server in your network, you may also need to configure the firewall and antivirus settings:
For instructions on how to modify the firewall settings so that the Windows Firewall on the license server allows Tekla Structures licensing traffic, see:
Allow exceptions in firewall for lmgrd.exe and tekla.exe: Windows Server 2008
Allow traffic in fixed TCP/IP ports: Windows 7, 8, 8.1, 10 and Windows Server 2012
In addition to Windows Firewall, the information given also applies to firewalls from other vendors.