Resolving "Network Error" via Firewall Settings

Issue Summary

The user’s internet connection is working (they can visit the website), but the software itself is being blocked from communicating with the server. This is usually caused by third-party security software aka anti-virus software incorrectly flagging the app.

Step 1: Unblock via Traffic Firewall

1. Open Security Software: Launch your security manager (e.g., 360 Security Center).
2. Locate Traffic Firewall: Go to the "Network Optimization" or "Traffic Firewall" section.
3. Find CAD Reader: Look for CADReader in the list of running applications. (Note: The software must be open for it to appear in the list).
4. Allow Access: If you see a "Blocked" or "Disabled" icon next to it, click the settings icon and select "Allow Network Access."

Step 2: Deep Reset (If the block persists)

If the software is automatically re-blocked after following Step 1:

1. Locate Installation Folder: In the Firewall list, right-click CAD Reader and select "Open File Location."
2. Delete Core File: Manually delete the cadreader.exe file from that folder.
3. Reinstall: Download a fresh installer from the official site and reinstall it into the exact same folder path.
4. Re-authorize: Repeat Step 1 to ensure the new installation is permitted to access the network.

Additional Network Troubleshooting Tips

The article also lists other common network scenarios the user should be aware of:

• Can't access website at all: Suggest switching to a mobile hotspot or checking the local Hosts file.
• HTTP works, HTTPS fails: This is often a corporate IT restriction; users should contact their IT department for permissions.
• "Internal Server Error": This usually indicates an outdated or unofficial version; the solution is to reinstall the official version.