Solidworks Host File Block Fix «2025»
You did Method 1. You restarted. An hour later, the block is back. Why?
Reason A: Antivirus "Ransomware Protection"
Reason B: SolidWorks Installation Manager (SOLIDWORKS SwActivation)
Reason C: The Odyssey Client (VPN Software)
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?
Note: This draft assumes the "fix" refers to attempting to block SolidWorks license verification servers via the Windows hosts file to bypass licensing (piracy). I have framed this as a warning against that practice.
The hosts file is a plain text file that maps hostnames to IP addresses. When you type a web address, your PC checks this file before asking the internet's DNS servers. solidworks host file block fix
How it relates to SolidWorks:
SolidWorks background processes (e.g., sldworks_fs.exe, SWLicensingService) periodically check in with Dassault Systèmes’ activation servers. By editing the hosts file, you redirect those server names to a dead end (usually 127.0.0.1 – your own computer).
The phrase "SolidWorks host file block fix" typically refers to two distinct scenarios: a legitimate troubleshooting step for server connectivity and a common step found in unofficial software "crack" guides to prevent license validation. 1. Legitimate Use: Fixing PDM Server Issues
Engineers often modify the Windows hosts file as a temporary fix when a workstation cannot communicate with the SOLIDWORKS PDM or License Manager server.
The Problem: DNS latency or VPN issues prevent the computer from resolving the server's name to its IP address.
The Fix: Manually map the server's IP to its name in the hosts file (C:\Windows\System32\drivers\etc\hosts) to bypass the DNS lookup.
Pros: Restores immediate access to vault files and licenses without waiting for IT to fix DNS. You did Method 1
Cons: It is a short-term workaround. If the server’s IP changes, the connection will break again. 2. Unofficial Use: Blocking License Checks
In the context of software bypasses, "blocking" entries are added to the hosts file to redirect SolidWorks' communication attempts away from official activation servers.
The Process: Entries like 127.0.0.1 activation.solidworks.com are added to ensure the software cannot "phone home" to verify its license status.
Risk: Antivirus programs (like SentinelOne or Webroot) may flag these modifications or block the installer's ability to edit the file, often leading to installation failures or "invalid license" errors. Summary Comparison Legitimate PDM Fix License "Block" Fix Purpose Connect to a local server Prevent online validation Action Maps IP to Name Redirects to Localhost Success Indicator Vault/License becomes reachable Software runs without activation Key Risk Connection breaks if IP changes Security risk; may violate TOS
How to Configure the Local HOSTS file to Resolve Server Name
Before we click "Save," let’s understand the battlefield. Reason C: The Odyssey Client (VPN Software)
The hosts file is a plain text file used by your operating system to map hostnames to IP addresses. It has priority over DNS (Domain Name System). When you type www.google.com, your PC checks the Hosts file first. If it finds an entry, it goes there without asking the internet.
How SolidWorks uses the internet: When you start SolidWorks, it checks for three things:
The "Block" Fix: By editing the Hosts file, you tell your computer to send SolidWorks' validation requests to a dead end (usually 127.0.0.1 - your own computer) instead of the real Dassault servers.
This stops the software from realizing it might be running on a floating license that expired, or prevents it from turning off features because it cannot reach the primary license server.
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.