The practice of using host file blocking for SolidWorks may appear to be a quick, harmless technical workaround, but it is fundamentally a dangerous path. What is a legitimate tool for server diagnostics becomes a serious liability when used to circumvent license enforcement.
In a typical piracy tutorial, you will see lines like this:
# SolidWorks License Block 0.0.0.0 solidworks.com 0.0.0.0 license.solidworks.com 0.0.0.0 licenses.solidworks.com 0.0.0.0 register.solidworks.com 0.0.0.0 activation.solidworks.com 0.0.0.0 geometricglobal.com 0.0.0.0 pub.solidworks.com 0.0.0.0 sw.global.plm.automation.siemens.com 0.0.0.0 lmt.solidworks.com 0.0.0.0 solidworkslicense.com 0.0.0.0 training.solidworks.com
If an organization inherits a machine previously used with unauthorized software, or if a user attempts an unapproved local installation, these entries will remain behind. This permanently blocks legitimate, legal installations from activating until the file is manually cleaned. Common Symptoms of a SolidWorks Hosts File Block
Aggressive firewalls, anti-malware tools, or third-party network monitors sometimes flag outbound licensing requests as suspicious traffic. To protect your system, they may automatically write block rules directly into your hosts file. 2. Leftovers from Software Cleanup Tools Solidworks Host File Block
: After saving, open the Command Prompt and type ipconfig /flushdns to apply the changes. 3. Common "Blocks" and Issues
A legitimate corporate proxy or firewall can sometimes block the specific IP addresses or ports used by SolidWorks for license checking, or it might interfere with the sldimdownloader.exe process, leading to connectivity errors. This is a standard operational issue.
| Issue | Description | |-------|-------------| | | Legitimate licenses risk deactivation or legal action. | | Blocked updates | Service packs, hotfixes, and new versions won't download or install. | | Cloud/3DEXPERIENCE features break | Collaboration, cloud storage, and online help fail. | | Subscription validation fails | Term-based licenses (e.g., annual) cannot check renewal status. | | Hosts file tampering detection | Some SolidWorks versions check the Hosts file integrity on launch. | | Windows Defender / AV flags | Modern antivirus detects and reverts Hosts file modifications for known software. | | SSL certificate errors | If the app expects HTTPS but gets localhost, cryptic SSL errors may appear. |
Users cannot successfully borrow or validate licenses from an external or hosted license manager because local traffic is being misrouted. The practice of using host file blocking for
: Save the file. You may need to restart your browser or SolidWorks for the changes to take effect. 3. SolidWorks "Blocks" (Internal CAD Feature)
Error messages stating "Could not obtain a license" or "Activation server unavailable."
Sometimes, users get the error: "SolidWorks cannot connect to the licensing server. Error -15,10."
Because the hosts file is a critical system file, Windows protects it from standard user modifications. Click the Windows menu. Type Notepad into the search bar. the SOLIDWORKS Installation Manager may fail.
: If the Windows built-in tools block downloaded .html files in the installation set, the SOLIDWORKS Installation Manager may fail. You must right-click the files and select Unblock in the properties menu.
ipconfig /flushdns
The hosts file ( C:\Windows\System32\drivers\etc\hosts ) maps hostnames to IP addresses.