Sometimes, malicious software or previous pirated versions of software modify your Windows hosts file to block license verification.
ETABS uses a file named lslicense.lic to locate the license server. If this file points to a wrong IP address or hostname, Error 120 appears.
If you are in a rush, run through this mental checklist to resolve Error 120: etabs license not recognized error 120 work
Note for antivirus users: Add exceptions for
lserv.exeandlmgrd.exe(located inC:\Program Files (x86)\Common Files\SafeNet Sentinel\Sentinel RMS License Manager\bin\).
If you have a physical purple or blue USB stick plugged into your machine, follow these steps: ETABS uses a file named lslicense
The most common culprit in modern computing environments is the Windows Firewall or third-party antivirus software. The CSI License Manager communicates via specific TCP/IP ports. By default, this is often Port 5053 (though it can vary based on the CSI_license.dat file).
If Windows Defender Firewall or an enterprise antivirus suite updates its definitions, it may suddenly decide that the traffic coming from lmgrd.exe (the license manager daemon) or ETABS.exe is suspicious, silently dropping the connection. This results in the "Not Recognized" error. Note for antivirus users : Add exceptions for lserv
Before diving into advanced fixes, run through this quick checklist:
If none of these work, proceed to the systematic fixes below.