Solidworks Host File Block Fix 🎁 Full

Dassault Systèmes (the maker of SolidWorks) has long since moved past simple host-file checks. Here is why the "fix" fails today:

Do not use Notepad shortcuts. Go directly to: C:\Windows\System32\drivers\etc\hosts Note: There is no file extension. It is just called hosts.

Sometimes, the Hosts file looks clean, but SolidWorks still fails. Why? Windows has a secondary security layer: The LMHosts file.

You need to block the specific domains that SolidWorks uses. Add the following lines at the end of the file:

# SolidWorks License Block List
127.0.0.1       localhost
127.0.0.1       swx.licensing.com
127.0.0.1       licensing.solidworks.com
127.0.0.1       register.solidworks.com
127.0.0.1       solidworks.com.licensing.com
127.0.0.1       lmtools.com
127.0.0.1       ###############################
::1             localhost

For advanced users (Network License Server Redirect): If you are running a local SolidWorks License Server (LMTOOLS) on your own machine (IP 127.0.0.1), you might need to redirect the service:

192.168.1.50    sw_dassault_lic_server    # Replace with your local server IP

Blocking activation servers is only legal if you:

You added the lines, but SolidWorks still gives you an error. Here is why.

Sometimes, even after deleting the lines, Windows caches the bad route.

Procedure:

If you want, I can (A) scan a pasted hosts file and highlight suspicious lines, or (B) generate a printable one-page checklist. Which would you prefer?

To fix a SOLIDWORKS "host file block" error, you typically need to map your license server's IP address to its hostname within the Windows hosts file or ensure your antivirus isn't preventing SOLIDWORKS from reading it. Quick Fix: Modifying the Windows Hosts File solidworks host file block fix

If your client machine cannot resolve the server name (DNS issue), you must manually map it to allow a connection to the SOLIDWORKS SolidNetWork License (SNL) Manager.

Run Notepad as Administrator: Click Start, type Notepad, right-click it, and select Run as Administrator.

Open the Hosts File: In Notepad, go to File > Open. Navigate to C:\Windows\System32\drivers\etc\. Change the file type filter in the bottom right from "Text Documents (*.txt)" to All Files.

Add Your Server Entry: At the bottom of the file (on a new line), type the server's IP address, press Tab, and then type the server's name. Example: 192.168.1.100 MyLicenseServer

Save and Flush DNS: Save the file. Then, open a Command Prompt and type ipconfig /flushdns to force Windows to recognize the new mapping. Troubleshooting "Can't Open/Write to Hosts File"

If you receive an error that the hosts file is blocked or cannot be modified, check these settings:

Antivirus Software: Programs like SentinelOne, ZoneAlarm, and Webroot are known to block changes to the hosts file. Look for settings like "Lock Hosts File" or "Prevent modification of HOSTS file" and temporarily disable them.

Read-Only Attribute: Right-click the hosts file, select Properties, and ensure Read-only is unchecked.

Correct Permissions: In file Properties > Security, ensure your user account has Write and Modify permissions. Related Network Blocks

If you still cannot connect after updating the hosts file, the block may be at the firewall level: Dassault Systèmes (the maker of SolidWorks) has long

Firewall Ports: Ensure TCP ports 25734 and 25735 are open for both Inbound and Outbound rules on both the server and client machines.

SNL Manager Setting: In the SolidNetWork License Manager, ensure the box "A firewall is in use on this server" is checked so it uses a static port for communication.

The "hosts file block" is a common fix used when SolidWorks cannot connect to its license server (Error -15, 10, 10061) or when DNS issues prevent the software from "finding" your workstation or server. 🛠️ The Direct Fix: Modifying the Hosts File

To bypass DNS translation issues and manually link an IP address to a server name, follow these steps: Open Notepad as Admin : Search for in the Start menu, right-click it, and select Run as Administrator Open the File : In Notepad, go to File > Open and navigate to: C:\Windows\System32\drivers\etc\ Change File Type : In the bottom-right corner of the "Open" window, change .txt documents to see the Add the Entry : Scroll to the very bottom and add a new line with the IP address Server Name 192.168.1.100 YourServerName Save and Flush : Save the file. Open a Command Prompt ipconfig /flushdns to force the system to recognize the change immediately. Hawk Ridge Systems ⚠️ Important: "Blocking" vs. "Unblocking" Unblocking (Legitimate Fix)

: Adding entries to the hosts file "unblocks" communication by telling your PC exactly where to look for the license server when the network fails to do so. Blocking (Cracked Software) : In unofficial versions, users often add entries like 127.0.0.1 activation.solidworks.com

to prevent the software from "calling home" to verify a license. This is a common cause for Activation Wizard Error 72 or permanent lockouts if the software detects tampering. 🔍 Additional Connectivity Troubleshooting

If the hosts file edit doesn't work, the "block" might be elsewhere:

The fluorescent lights of the engineering bay hummed with a low, mocking vibrato as Elias stared at the spinning blue cursor on his screen. It was 11:42 PM, and the deadline for the "Project Chimera" prototype was less than eight hours away.

Elias was a veteran designer, the kind who could navigate SolidWorks with his eyes closed. But tonight, the software was a ghost. Every time he tried to launch it, the splash screen would hang on "Verifying License," only to vanish into the digital ether without so much as an error message.

"Come on, you piece of garbage," Elias muttered, his fingers drumming a frantic rhythm on his mahogany desk. For advanced users (Network License Server Redirect): If

He had already checked the server. He’d restarted his workstation three times. He’d even sacrificed a lukewarm cup of coffee to the silicon gods. Nothing. It was as if his computer had suddenly decided SolidWorks didn't exist.

Desperate, he pulled up his laptop and began a frantic deep-dive into the darker corners of tech forums. He bypassed the official support pages—they were filled with "reinstall the program" advice that he didn't have time for. Finally, on page four of an obscure sysadmin board, he found a thread titled: “The Invisible Wall: When Your System Blocks the Handshake.” The culprit? The Hosts file.

Elias realized that a recent security "patch" from the IT department might have flagged the licensing server’s IP as a suspicious domain. In an effort to keep the network safe, the Windows system had effectively put a blindfold on SolidWorks, preventing it from seeing its own license manager. With a surge of adrenaline, Elias went to work.

The Search: He navigated to the heart of the machine: C:\Windows\System32\drivers\etc.

The Guardian: He right-clicked hosts and opened it with Notepad, but he did it with Administrative privileges—the "skeleton key" of the Windows world.

The Reveal: There it was. At the very bottom of the text file, a series of lines had been added. They were redirecting the SolidWorks licensing URLs to 127.0.0.1—the digital equivalent of a dead-end street.

The Erasure: With a steady hand, he highlighted the offending lines and hit Delete. He felt like an archaeologist brushing dust off a hidden inscription.

The Seal: He saved the file, closed the window, and held his breath.

He moved his mouse back to the workstation. He double-clicked the red SolidWorks icon.

The splash screen appeared. Initialising... Loading Registry... and then, with a triumphant chime, the interface bloomed into life. The assembly for Project Chimera loaded in all its complex, geometric glory.

The "invisible wall" was gone. Elias leaned back, the hum of the lights no longer sounding like a mockery, but a celebration. He had defeated the block, and the prototype was back on track.