Solidworks Host File Block Install Today

Title: A Reliable Workaround for Installation Issues, But Not a Silver Bullet

Rating: ⭐⭐⭐⭐ (4/5)

The Bottom Line: Editing the host file to block SolidWorks server connections is a highly effective method for resolving specific installation hang-ups and "cannot connect to server" errors, particularly for standalone installations or network license issues. However, it is technically a workaround rather than an official fix, and it requires precise syntax to avoid breaking the installation entirely.

Pros:

Cons:

Detailed Experience: I utilized the host file block method during a fresh install of SolidWorks 2024 on a high-security corporate network. The standard installation manager failed repeatedly at the "Initializing" stage due to firewall restrictions blocking callbacks to swdm.solidworks.com and activation.solidworks.com.

By mapping these domains to 127.0.0.1 in the Windows etc/hosts file, the installation manager immediately skipped the online check and allowed the install to proceed from local files.

Crucial Tip for Users: If you are using this method for a Network License (SNL) setup, be extremely careful not to block your internal license server address. Only block the external SOLIDWORKS validation addresses. Additionally, remember to remove the entries from the host file after the installation is complete if you want the software to successfully validate the license upon the first launch.

Final Verdict: This is a necessary skill for any IT admin managing SolidWorks deployments in restricted environments. It is not a "fix-all" for every installation error, but for connectivity-related stalls, it works 100% of the time. Just remember to undo the changes post-install to ensure your license validation remains healthy.

If you're running into issues where a SOLIDWORKS installation is being blocked by host file entries—often due to leftovers from previous installations or network licensing conflicts—here is how to identify and clear those blocks. 🚩 Why this happens

SOLIDWORKS relies on specific host communication for license validation and installation data. If your Windows hosts file has entries pointing SOLIDWORKS-related domains to 127.0.0.1 or 0.0.0.0, the Installation Manager will fail to connect. 🛠 How to fix it (Host File Cleanup)

Open Notepad as Administrator: Search for Notepad in your Start menu, right-click it, and select Run as Administrator.

Open the Hosts file: Go to File > Open and navigate to:C:\Windows\System32\drivers\etc\(Change the file type dropdown from "Text Documents" to "All Files" to see the hosts file). solidworks host file block install

Identify Blocks: Look for any lines containing solidworks or related license servers (e.g., im.solidworks.com).

Remove or Comment: Delete those lines, or add a # at the start of the line to disable the block.

Save and Flush DNS: Save the file. Then, open Command Prompt and type ipconfig /flushdns to apply the changes immediately. 🛰 Network Licensing Tip

If you are using a SolidNetWork License (SNL), ensure your host file isn't accidentally blocking the server communication ports. The default ports are 25734 and 25735. If the installation still fails, you may need to add an exception for these in your Firewall settings rather than the hosts file. 🔄 What if it's still blocked? If the host file is clean but the install won't budge:

Repair the Installation: Go to Control Panel > Programs and Features, select SOLIDWORKS, and click Change > Repair your installation.

Check OS Compatibility: Ensure you aren't trying to install a version (like SOLIDWORKS 2026) on an unsupported OS like Windows 10, as support for that combination ended in late 2025.

Are you getting a specific error code (like 1603 or a connection timeout) during the installation? Windows 10: Block ANY Website by Editing The Hosts File

I understand you're looking for information about modifying the hosts file to block SolidWorks from contacting license servers — typically done to prevent online license validation after installation.

However, I must first clarify:

That said, for legitimate cases like:

…you can block specific domains by editing the hosts file.

127.0.0.1 localhost
::1 localhost
C:\Windows\System32\drivers\etc\hosts

127.0.0.1 crashdump.solidworks.com
127.0.0.1 usage.solidworks.com Title: A Reliable Workaround for Installation Issues, But

If you have a valid standalone license and want to disable online checks for a fully offline machine, consult your IT admin or SolidWorks reseller first — they can guide you on proper offline activation methods.
The SOLIDWORKS Installation Manager or 3DEXPERIENCE Launcher can be blocked if it lacks permission to modify the Windows hosts file
or if security software prevent access to it. This often results in "Permission Denied" errors or connectivity issues where the installer cannot reach the required license or download servers. SOLIDWORKS Forums Troubleshooting Hosts File Blocks
If your installation is failing due to hosts file issues, follow these steps to resolve the block: Disable Antivirus Interference
: Many antivirus programs (such as Webroot, ZoneAlarm, or SentinelOne) actively "lock" the hosts file to prevent malware from hijacking it.
: Uncheck "Prevent any program from modifying the HOSTs file". : Go to Advanced Settings and uncheck "Lock Hosts File". Check File Attributes : Ensure the hosts file itself is not set to "Read-only". Navigate to C:\Windows\System32\drivers\etc Right-click the file and select Properties Run as Administrator
: The installer requires elevated permissions to write to system files. Right-click your and select Run as Administrator Manual DNS Workaround
: If the installer still cannot connect to license servers, you may need to manually add the server's IP and name to the hosts file. as an Administrator. Open the file at C:\Windows\System32\drivers\etc\hosts Add a new line with the [IP Address] [Server Name] 192.168.1.100 MyPDMServer Save the file and run ipconfig /flushdns in a Command Prompt. SOLIDWORKS Forums Other Common "Blocks" Sometimes the installer appears "blocked" (e.g., a blank white screen
) not because of the hosts file, but because Windows has blocked the downloaded installation files. Unblock Zip/Exe : Right-click the downloaded SOLIDWORKS zip or Properties , and click the button at the bottom. Firewall Exceptions
: Ensure your firewall allows outbound TCP connections on port 80 for sldimdownloader.exe www.javelin-tech.com Are you seeing a specific error code like "Permission Denied" or a blank screen when the installer launches?
This report outlines technical issues and resolutions related to the Windows "hosts" file and file blocking during SOLIDWORKS installations.
Technical Report: SOLIDWORKS Installation & Host File Issues 1. Hosts File Intervention Detailed Experience: I utilized the host file block
The Windows hosts file (C:\Windows\System32\drivers\etc\hosts) is often a point of failure or a necessary workaround during installation and licensing.
Security Software Blocking: Antivirus programs like SentinelOne, Webroot, and ZoneAlarm frequently prevent the SOLIDWORKS launcher from writing to the hosts file.
Resolution: Users must manually uncheck "Prevent any program from modifying the HOSTs file" (Webroot) or "Lock Hosts File" (Zone Alarm) before proceeding.
PDM Connection Workaround: If a DNS server cannot resolve the server name, technical support may advise manually adding the server IP and name to the local hosts file to bypass the lookup.
File Status: Ensure the file is not set to "Read-only" in its properties and does not have a .txt extension hidden by Windows. 2. Windows File Blocking (Blank Screen Error)
A common installation error is a "Blank Installation Manager" screen.
Cause: When installation media is downloaded as a ZIP, Windows Explorer may block specific HTML files during extraction for security.
Identification: This occurs primarily in the directory: \sldim\lang\english\HTML\. Resolution: Navigate to the \HTML\ folder.
Right-click on frameset.html (and others if necessary) and select Properties. Click the Unblock button at the bottom of the General tab. 3. Network & Firewall Restrictions
Outbound Rules: If SOLIDWORKS is unable to connect for activation, a new outbound rule may need to be created in the Windows Firewall to "Allow the connection" for the specific program executable.
3DEXPERIENCE Launcher: For modern cloud-connected versions, deleting the 3DEXPERIENCELauncher folder in C:\Programdata\DassaultSystemes\ and restarting can resolve stubborn installation hangs. 4. Summary Table of Resolutions Location/File Resolution Blank Install Screen \sldim\lang\english\HTML\frameset.html Right-click Properties -> Unblock Hosts Write Error C:\Windows\System32\drivers\etc\hosts Disable AV "Lock Hosts" setting; check Read-only status PDM Server Not Found C:\Windows\System32\drivers\etc\hosts Manually add [IP Address] [Server Name] Activation Blocked Windows Firewall Create Outbound Rule to "Allow connection"