Did this issue start after a recent , antivirus installation , or network change ?
When you install SOLIDWORKS, it may create entries in the host file to facilitate communication between the software and the license server. However, sometimes these entries can become corrupted or blocked, causing issues with the software. Here are some common reasons that can lead to a host file block:
SOLIDWORKS "hosts file block" typically refers to an error where the installer or software cannot write to the Windows hosts file, often due to aggressive antivirus settings or a read-only attribute. This is also a common workaround used to resolve SOLIDWORKS PDM
: The file itself may be set to read-only.
💡 Add a comment line above to remind yourself why you did this: # SolidWorks block list - added March 2026
This comprehensive guide explains how the Windows Hosts file impacts SolidWorks, how unauthorized blocks get introduced, and the exact step-by-step process to fix these blocks to restore full software functionality. Understanding the Windows Hosts File and SolidWorks
By default, Notepad only looks for .txt files. In the bottom-right corner of the Open dialog box, change the dropdown menu from to All Files ( . ) .
Alternatively, type a # symbol at the very beginning of the line to turn it into a comment, which disables the block.
If you are operating on a company network using a specific corporate license manager, add your internal server IP address paired with your SolidWorks port number (typically 25734 or 25735 ): [Your_Server_IP_Address] [Your_Server_Name] Use code with caution. Step 4: Save and Flush DNS Click > Save (or press Ctrl + S ). Close Notepad.
You will see a file named (with no file extension). Select it and click Open . Step 3: Identify and Remove the SolidWorks Blocks
Search for in the Start menu. Click on Outbound Rules in the left-hand pane.
Solidworks Host File Block Fix New! Jun 2026
Did this issue start after a recent , antivirus installation , or network change ?
When you install SOLIDWORKS, it may create entries in the host file to facilitate communication between the software and the license server. However, sometimes these entries can become corrupted or blocked, causing issues with the software. Here are some common reasons that can lead to a host file block:
SOLIDWORKS "hosts file block" typically refers to an error where the installer or software cannot write to the Windows hosts file, often due to aggressive antivirus settings or a read-only attribute. This is also a common workaround used to resolve SOLIDWORKS PDM solidworks host file block fix
: The file itself may be set to read-only.
💡 Add a comment line above to remind yourself why you did this: # SolidWorks block list - added March 2026 Did this issue start after a recent ,
This comprehensive guide explains how the Windows Hosts file impacts SolidWorks, how unauthorized blocks get introduced, and the exact step-by-step process to fix these blocks to restore full software functionality. Understanding the Windows Hosts File and SolidWorks
By default, Notepad only looks for .txt files. In the bottom-right corner of the Open dialog box, change the dropdown menu from to All Files ( . ) . Here are some common reasons that can lead
Alternatively, type a # symbol at the very beginning of the line to turn it into a comment, which disables the block.
If you are operating on a company network using a specific corporate license manager, add your internal server IP address paired with your SolidWorks port number (typically 25734 or 25735 ): [Your_Server_IP_Address] [Your_Server_Name] Use code with caution. Step 4: Save and Flush DNS Click > Save (or press Ctrl + S ). Close Notepad.
You will see a file named (with no file extension). Select it and click Open . Step 3: Identify and Remove the SolidWorks Blocks
Search for in the Start menu. Click on Outbound Rules in the left-hand pane.