You cannot edit the hosts file without administrative privileges. Locate the file named hosts . Right-click on hosts and select > Notepad .
Type the following command and press Enter: ipconfig /flushdns
By far the most common cause. If a computer previously hosted an unauthorized or cracked version of SolidWorks (such as those bundled with "SSQ" or "SolidSquad" activators), the crack script automatically modifies the Windows Hosts file. It does this deliberately to prevent the illegal software from "phoning home" to Dassault Systèmes and getting flagged. If you later try to install a legitimate, legal license on that same machine, the old blocks remain and break the official activation process. Step-by-Step Guide to Fix the SolidWorks Hosts File Block
: The local installation cannot communicate with the automated activation servers. solidworks host file block fix
If you are using a floating network license (SNL) in a corporate environment and your DNS is failing to resolve the license server's name, you can use the hosts file to manually route it. Go to the bottom of the file.
Double-click the file named (it will not have a file extension). Step 2: Identify and Remove SolidWorks Blocks
IT policies or security software have wrongly added licensing URLs to the hosts file. How to Perform the SolidWorks Host File Block Fix You cannot edit the hosts file without administrative
The Windows hosts file is a plain text file used by the operating system to map hostnames (like activation.solidworks.com ) to IP addresses. It functions as a local DNS lookup table, taking precedence over DNS servers.
: Ensure there isn't an Outbound Rule blocking the SOLIDWORKS executable ( SLDWORKS.exe ).
If cleaning out the hosts file does not instantly solve your SolidWorks launch issue, the block might exist at a deeper system or network level. Check these three common culprits: 1. Windows Firewall and Port Rules Type the following command and press Enter: ipconfig
127.0.0.1 licensing.solidworks.com 127.0.0.1 register.solidworks.com
Sometimes, the Hosts file looks clean, but SolidWorks still fails. Why? Windows has a secondary security layer: .