You added the lines, but SolidWorks still gives you an error. Here is why.
He saved the file, closed the window, and held his breath.
If editing the Hosts file does not fully resolve the license block, your system security settings or residual system data may still be interfering with the activation check. 1. Configure Windows Defender Firewall solidworks host file block fix
The Windows hosts file acts as a local address book that operating systems check before querying an external DNS server. When an IT network experiences latency, or a local router fails to translate a server name (e.g., PDM-Server-01 ) into a machine-readable IP address, SolidWorks throws connection timeout and license retrieval errors. Symptoms of a Host-Related Network Block
Search for in the Start menu. Click on Outbound Rules in the left-hand pane. You added the lines, but SolidWorks still gives you an error
This is the pure "Host File Block Fix" for 90% of users.
Which (e.g., 2024, 2025) are you currently running? If editing the Hosts file does not fully
Corrupted local cache files often cause validation loops even after network connections are fixed. Close SolidWorks completely. Press Windows Key + R to open the Run dialog box. Type %programdata% and click . Locate the folder named FLEXnet and open it.
Temporarily disable the "Lock Hosts File" or "Prevent programs from modifying HOSTs" setting in your antivirus dashboard. Read-Only Attribute Right-click the file and select Properties is unchecked. Permission Fix Properties > Security , ensure your user account has Full Control Microsoft Learn 3. Fixing Blocked Installation Files
To resolve issues where SOLIDWORKS (particularly PDM) cannot connect to a server or where an installation is blocked by the Windows file, follow this guide to modify or unblock the file. 1. Fixing DNS/Connectivity via the Hosts File