Etabs — License Not Recognized Error 120

If your license file has become corrupted, ETABS will fail to recognize it.

Upon launching ETABS, the following error message appears:

"License not recognized. Error 120"

The software initialization fails immediately after this message. No further functionality is accessible. The issue is reproducible on every launch attempt.

An old license manager is a common cause of Error 120, especially after installing a new ETABS major release.

Error 120 is a common yet frustrating licensing issue that occurs when ETABS (or CSI Software) cannot communicate with the license server or local license file. It typically appears during software startup, blocking access to the program. While the error message is vague, it usually points to one of three root causes: network/server communication failure, outdated license manager tools, or corrupted license path settings.

Before diving into the fix, it helps to understand why this happens. Error 120 generally pops up when: etabs license not recognized error 120

Follow these steps in order. Start with the simplest (restarting services) and move toward more complex solutions (file editing).

Error 120 is rarely a hardware failure. In 90% of cases, it is caused by either a broken path in the lservrc file, an overzealous antivirus, or user permissions. Work through the steps methodically, and you will likely be back to modeling shear walls and moment frames within 10 minutes.

Have you fixed Error 120 with a different method? Let us know in the comments below!

Error #120 typically indicates that the license file is incomplete or corrupted

. This usually happens when the activation process was interrupted or if a standalone license file wasn't fully registered by the system. CSI Knowledge Base Recommended Solutions Deactivate and Reactivate

: For standalone licenses, the most effective fix is to first deactivate your current license and then perform a fresh reactivation using your activation key. Run as Administrator

: Ensure you are running the license activation tool (located in the CSiLicensing If your license file has become corrupted, ETABS

subfolder) with administrative rights to allow it to write the necessary files correctly. Verify Internet Access

: Your machine must have an active internet connection to communicate with the CSI activation servers. Check that Ports 80 and 443 are not blocked by your firewall or antivirus. Update Sentinel Drivers : If you use a hardware USB key, ensure the Sentinel System Driver is installed and up-to-date. Check System Date

: An incorrect system date can cause license validation to fail. Ensure your computer’s date and time are synchronized. CSI Knowledge Base Troubleshooting Connectivity (Network Licenses)

If you are seeing this on a client machine using a network license: Check Server Connection : Ensure the client can "see" the license server. Use LMHOST.INI : Create a file named LMHOST.INI

in the ETABS installation folder containing the IP address of your license server to speed up the detection process. www.csicertifications.us For further assistance, you can refer to the official CSI Knowledge Base

or contact their support team if the file continues to appear corrupted. CSI Knowledge Base Are you using a standalone activation key network license server for your ETABS installation? Licensing errors generated when running CSI software

In structural engineering software, Error #120 in Computers and Structures, Inc. (CSI) ETABS indicates that the license file is incomplete or improperly activated. This error typically prevents the software from launching and is often rooted in corrupted registry entries or a mismatch between the installed license and the workstation's configuration. Core Causes of Error #120 Upon launching ETABS, the following error message appears:

Incomplete License File: The lservrc file, which contains the authorization codes, may be missing critical components or failed to write correctly during activation.

Registry Corruption: Errors often arise from corrupted registry entries during the installation phase, which can block the software from correctly identifying a valid license.

Configuration Mismatches: For standalone licenses, changes to the machine's hardware ID (locking criteria) or system date formats can lead to the license being "unrecognized". Troubleshooting and Resolutions

Standard official procedures for resolving Error #120 vary depending on the license type:

Standalone Licenses: The primary solution is to deactivate the current license and then reactivate it using the activation key provided by CSI. This refreshes the local license file and ensures it matches the machine's current locking code.

Network Licenses: Users should verify the connection between the client machine and the license server. Creating an LMHOST.INI file in the product's installation folder with the server's IP address can help the software locate the license more reliably.

Installation Repair: If reactivation fails, running a FixIt tool or performing a clean uninstallation followed by a system reboot and re-installation is recommended to clear corrupted registry data. Alternative Approaches

Some users employ third-party tools like "Run as Date" to bypass licensing issues related to expired trial periods by tricking the software into seeing a historical system date. However, official CSI documentation emphasizes that legitimate activation requires administrative rights and open internet ports (80 and 443) to communicate with their activation servers.