Error #120: License Not Recognized typically indicates that the software can see a license file, but it is incomplete, corrupted, or mismatched with your system's current hardware signature CSI Knowledge Base Immediate Fixes Deactivate and Reactivate : For standalone licenses, the standard CSI America Knowledge Base recommendation is to deactivate the license via CSILicenseAssistant.exe (found in the CSiLicensing
subfolder) and then reactivate it using your activation key. Verify Date/Number Format
: Sometimes this error occurs because the machine's regional settings are not set to English (United States) . Change your date format to mm/dd/yyyy
and your decimal separator to a period (.) to ensure the license file is read correctly. Check System UUID
: If your computer lacks a valid UUID (shows as all 'F's), the license cannot "lock" to your hardware. You can check this by running wmic csproduct get uuid in the Command Prompt. CSI Knowledge Base Service & Environment Troubleshooting Restart Sentinel Services : Ensure the Sentinel RMS License Manager is running. Open Services.msc
, locate "Sentinel RMS License Manager," right-click it, and select Sync Locking Codes echoid.exe wechoid.exe
(found in the ETABS installation folder) to confirm that your machine’s Ethernet Address and UUID match the criteria the license was originally issued for. If you have reformatted your PC or changed hardware, you must contact CSI Support to reset the license. Remove Corrupted Files : Check the C:\Windows folder for files with a
extension. Deleting these files and then resetting toolbars within ETABS (Options > Reset Toolbars) has been known to clear internal registry conflicts that trigger recognition errors. CSI Knowledge Base Summary of Troubleshooting Tools These utilities are located in the CSiLicensing subfolder of your ETABS installation: Licensing errors generated when running CSI software Jul 7, 2568 BE —
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
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.
The "ETABS License Not Recognized Error 120" is a frequent hurdle for structural engineers using Computers and Structures, Inc. (CSI) software. This error typically surfaces when the Sentinel RMS License Manager cannot validate your credentials, effectively locking you out of your design projects.
Understanding the root cause and following a systematic troubleshooting guide can get you back to work in minutes. What Causes Error 120 in ETABS?
Error 120 is a communication failure between the ETABS application and the licensing service. The most common culprits include: etabs license not recognized error 120
Service Stoppage: The Sentinel RMS License Manager service is not running.
Environment Variables: Missing or incorrect system paths pointing to the license server.
Network Blockage: Firewalls or antivirus software preventing the "lsans.exe" process from communicating.
Version Mismatch: Using an outdated license manager with a newer version of ETABS.
License Expiration: The standalone or network license has reached its end date. Step-by-Step Solutions to Fix Error 120 1. Restart the Sentinel RMS License Manager
Often, the license service simply hangs. Restarting it refreshes the connection. Press Win + R, type services.msc, and hit Enter. Locate Sentinel RMS License Manager.
Right-click it and select Restart. If it isn't running, click Start. Ensure the "Startup Type" is set to Automatic. 2. Configure Environment Variables
If ETABS doesn't know where to look for the license, it will trigger Error 120.
Right-click "This PC" and go to Properties > Advanced System Settings. Click Environment Variables. Under "System Variables," click New. Variable Name: LSFORCEHOST
Variable Value: Enter your server's IP address or computer name (use localhost if it's a standalone license). Restart ETABS. 3. Verify the "lshost" File ETABS checks a local text file to find the license server.
Navigate to the ETABS installation folder (usually C:\Program Files\Computers and Structures\ETABS [Version]). Look for a file named lshost.
Open it with Notepad and ensure it contains only the hostname or IP address of your license server. Save and close. 4. Firewall and Antivirus Exceptions
Your security software might be flagging the license check as suspicious activity.
Add an exception for lsans.exe (the license manager executable).
Open UDP Port 5093, which is the default port used by Sentinel RMS.
Temporarily disable your antivirus to see if the error persists; if it resolves, you need to whitelist the CSI folder. 5. Run the License Request Tool
If the license file itself is corrupt, you may need to re-activate. Go to the ETABS installation directory. Run CSIRegister.exe or LicenseRequest.exe.
Check if your "Locking Code" matches the one tied to your active license. Preventing Future License Errors
📍 Keep Software Updated: Ensure both ETABS and the Sentinel RMS License Manager are the latest versions provided by CSI.📍 Static IP Addresses: If using a network license, assign a static IP to the server to prevent the LSFORCEHOST path from breaking.📍 Stable Internet: For cloud-based licenses, a flickering connection can trigger Error 120 mid-session. Error #120: License Not Recognized typically indicates that
If none of these steps work, it may be time to contact CSI Technical Support with your "echoid.exe" results to verify your license status. To help you resolve this more specifically: Are you using a standalone or network license? Which version of ETABS are you currently running?
Did this error occur after a Windows update or a hardware change?
Knowing these details will allow me to provide the exact file paths or registry keys you need.
This error usually triggers when the software can find a license file, but the data within that file is missing required segments or doesn't align with the machine's specific "Locking Code" (which includes the Ethernet address, CPU info, and UUID). Primary Fixes
Reactivate the License: For standalone versions, the official recommendation is to deactivate the current license and then reactivate it to refresh the local license file.
Fix Corrupted Registry Entries: Sometimes registry errors during installation cause this mismatch. You can try running a Microsoft FixIt tool or a clean reinstall: Uninstall all previous versions (including trials). Reboot your machine. Perform a fresh installation.
Check Date/Time Settings: In some cases, inconsistent regional settings or system dates can interfere with license validation. Ensure your system date and number format are set to US (mm/dd/yyyy). Technical "Deep Story" Workarounds
If the standard reactivation doesn't work, the community often points to these deeper causes:
UUID Invalidity: If your computer lacks a valid UUID (showing as FFFFFFFF-FFFF-FFFF...), the license manager may fail to lock the software to your hardware.
Clock-Manipulation ("RunAsDate"): For older versions where licenses have expired, some users employ tools like RunAsDate to trick the software into thinking it's running during the valid license period, though this is a workaround rather than a formal fix.
Cleaning Temporary Files: Deleting *.tb2 files in the C:\Windows folder and resetting toolbars within ETABS can occasionally clear UI-related license glitches.
Note: If you are using a network license, Error 120 may require your IT administrator to update the License Manager (LM) to a version compatible with your specific ETABS release.
Solving the ETABS "License Not Recognized" Error 120: A Troubleshooting Guide
Structural engineers rely on ETABS for critical design tasks, so encountering a licensing error right when you need to run a simulation can be frustrating. One of the most common issues users face is Error 120: License Not Recognized According to the official CSI Knowledge Base , Error 120 typically indicates that the license file is incomplete or corrupted.
If you're staring at this error message, don't worry. Here is a step-by-step guide to getting your software back online. 1. Deactivate and Reactivate (Standalone Licenses)
For those using a standalone license, the most direct solution recommended by experts is a simple "reset" of your activation. CSILicenseAssistant.exe found in the CSiLicensing subfolder of your ETABS installation directory. Navigate to the "License" tab and select Deactivate Once successful, select and re-enter your activation key. 2. Verify System Date and Time
Licensing servers are highly sensitive to "time tampering." If your computer's system date is incorrect, the license file may be flagged as invalid.
Ensure your date and time are synchronized with an internet time server. CSI Support Guide suggests using the US date format (mm/dd/yyyy)
to avoid compatibility issues with certain license managers. 3. Update Sentinel Drivers Conclusion ETABS Error 120 is a nuisance, but
ETABS uses Sentinel LDK technology to manage licenses. If your drivers are outdated or the Sentinel License Manager service isn't running, the software won't "see" your valid license. Check the Service: Open Windows "Services" and ensure the Sentinel License Manager is set to "Running". Reinstall Drivers: You can often find the driver installer (usually SetupSysDriver.exe or similar) within the folder in your CSI program directory. 4. Check for Corruption in the lservrc File If the solutions above don't work, your file (the actual license file) might be incomplete. Locate the file in your ETABS installation folder.
If the file size is 0KB or it appears empty when opened with Notepad, it is likely corrupted. You may need to contact CSI Technical Support to have your license file reissued or validated. 5. Avoid "Native Image Generation" During Install
If you are performing a fresh installation and keep hitting this error, some users found success by
the "Perform native image generation" option during the installation process. This can sometimes prevent the license initialization from being blocked by system security. Summary Checklist Reactivate Refreshes the local license token. Prevents "invalid date" flags. Check Services Ensures the Sentinel License Manager is active. Update Drivers Connects the hardware/software ID to the license.
was staring at the deadline for the skyscraper’s seismic analysis when the screen flashed a mocking red. The high-stakes project was due in four hours, but ETABS refused to cooperate, displaying the dreaded message: "License Not Recognized Error #120."
It was a classic structural engineer's nightmare. According to the CSI Knowledge Base, Error 120 typically signifies an incomplete license file. For Maya, this meant her software couldn't verify her credentials, likely because her standalone license had hit a snag during a recent system update.
She didn't panic—she'd seen this before. Following official troubleshooting advice, she knew the primary fix was to deactivate and then reactivate the license. But as she worked, she remembered a few other tricks her colleagues used for this specific glitch:
Check the System Date: Sometimes a simple mismatch in the machine's date can invalidate a license file.
Run as Administrator: Registry entries can get corrupted during installation; running the program with Administrator rights can sometimes bypass these permission hurdles.
Registry Fixes: If deactivation failed, she might need a Microsoft FixIt tool to clear out corrupted registry entries left behind by previous versions.
If you're facing this specific issue, this walkthrough shows how to resolve the license recognition error step-by-step:
ETABS Error 120 is a nuisance, but it is rarely fatal to your project. In 90% of cases, the issue is a firewall blocking the handshake or a service that needs a restart.
If you have tried all the steps above and are still seeing "License Not Recognized," it is likely a hardware ID mismatch or a license borrowing issue. In that case, contacting CSI Support directly with your User ID and Locking Code is the best path forward.
Did these solutions work for you? Let us know in the comments below!
Based on user reports and CSI documentation, the following steps resolve the issue in most cases:
| Step | Action |
|------|--------|
| 1 | Restart the CSI License Manager on the server (via Services > CSI License Manager). |
| 2 | Verify the license file – Ensure lservrc is in the correct folder (usually C:\Program Files\Common Files\CSI\Licenses\). |
| 3 | Check network connectivity – From the client PC, ping the license server and telnet to port 27000. |
| 4 | Update LMServer – Download the latest License Manager from CSI’s website. |
| 5 | Reconfigure license path – In ETABS, go to Help > License > Configure, and specify the correct server or local file. |
| 6 | Temporarily disable firewall/antivirus – Test if the error disappears; if so, add an exception for lmgrd.exe and ETABS.exe. |
The most frequent cause of Error 120 is Windows Security blocking the ETABS.exe file from verifying the license.
If you are running a newer version of ETABS (v18, v19, 20, or 21), CSI changed how the licensing service runs in the background.
Windows Key + R on your keyboard.services.msc and hit Enter.Restarting this service forces the computer to "re-read" the license file, which often clears Error 120 immediately.