Solidworks | Host File Block

Note: Domains can change. If the software manages to connect, you may need to use a network monitoring tool (like Wireshark) to identify new domains.

Modifying hosts files to bypass activation on unlicensed software is against the SolidWorks End User License Agreement (EULA).

When the Windows hosts file contains entries that redirect or block SolidWorks activation and verification servers, users encounter persistent licensing errors, failure to connect to the SolidWorks Installation Manager, or sudden software deactivations.

What or code is appearing on your screen?

When your system cannot reach the SolidWorks servers due to a hosts file block, you will likely encounter specific operational errors: Solidworks Host File Block

If you use a network license, you might see FlexNet license finder prompts asking for a valid server location because the local machine cannot resolve the network path. How to Check and Edit Your Hosts File

Security software like SentinelOne, ZoneAlarm, or Webroot may prevent modifications to the hosts file as a security measure.

The activation wizard fails to initiate, or returns a generic error code indicating an inability to resolve the destination network path. Step-by-Step Guide to Unblocking SolidWorks

By adding specific SolidWorks URLs to this file and redirecting them to 127.0.0.1 (localhost), you effectively block your computer from communicating with SolidWorks servers. This is typically done to prevent the software from "phoning home" to verify licenses or check for updates. Note: Domains can change

Understanding the SolidWorks Hosts File Block The hosts file is a local text file used by operating systems to map hostnames to IP addresses. When a computer attempts to connect to a server, it checks the local hosts file before querying external Domain Name System (DNS) servers.

Sometimes, your AV software will "protect" the hosts file and revert your changes. Disable it temporarily while editing.

What specific or behavior are you experiencing?

At the bottom of the file, you will add lines that redirect SolidWorks servers back to your local machine ( 127.0.0.1 ). When the Windows hosts file contains entries that

Some legitimate license holders prefer to block telemetry data. While SolidWorks collects diagnostic data to improve the software, strict IT security policies (e.g., in defense or confidential manufacturing) require that the CAD workstations have absolutely zero outbound traffic to external cloud servers.

Scroll to the bottom of the file (below any lines starting with # ).

During activation, standard licensing errors appear, claiming the server is temporarily unavailable or your internet connection is down.