This means the app can’t reach our licensing/services over the Internet. It’s usually a network block, proxy setting, or firewall/content‑filter issue—not a bug in the simulator.
Note: CNC Simulator Pro requires Internet access to start and periodically while running.
Quick checks (1–2 minutes)
Internet works? Open a browser and load our website/help.
Restart the app and (if needed) the PC/router.
Try a mobile hotspot (phone tether). If it works on hotspot, your main network is blocking it.
Temporarily disable VPN and third‑party firewall to test. Restart the app and (if needed) the PC/router.
Try a mobile hotspot (phone tether). If it works on hotspot, your main network is blocking it.
Temporarily disable VPN and third‑party firewall to test.
Common causes & fixes
1) Firewall/AV blocks outbound HTTP
Allow
cncsimulator.exefor outbound connections.Ensure outbound HTTP (TCP 80) to our service domains is permitted.
Some corporate content filters block unknown apps—ask IT to allow our domains.
2) Proxy settings are required or incorrect
If start‑up fails, the app may offer to configure a proxy. Enter your proxy host, port, and credentials if your network uses one.
Windows → Settings → Network & Internet → Proxy: confirm the correct proxy or turn it off if you don’t use one.
Admins: keep WinHTTP and WinINET proxy settings consistent.
3) Captive portal / restricted Wi‑Fi
Some guest Wi‑Fi requires a login/acceptance page before Internet works. Open any website, complete the portal, then start the app.
4) DNS/VPN issues
If DNS fails (can’t resolve our domains), switch to automatic DNS or try a public DNS (temporarily) to test.
Some VPNs block unknown apps; test with VPN off.
5) Weak/unstable connection
Improve Wi‑Fi signal or use Ethernet/USB‑C dongle. Intermittent drops can prevent log‑in.
6) Rare service incident
If everything looks fine locally but start‑up still fails on multiple networks, it could be a temporary service issue. Try again a bit later and, if it persists, contact us with details (see below).
Advanced tests (optional)
Open PowerShell as a normal user and run:
# Test TCP reachability Test-NetConnection cncsimulator.com -Port 80
# Quick HTTPS fetch (should return HTML) iwr https://cncsimulator.com/help/g_codes.htm -UseBasicParsing | select -First 1
# Check system proxy (for admins) netsh winhttp show proxy
Include the outputs in your ticket if you still have issues.
What IT should allow
Outbound HTTP (TCP 80) from user PCs to our service domains.
If your organization uses an HTTP proxy, configure the proxy in Windows and in the app when prompted, or allow our domains to bypass authentication where policy permits.
Allow the app binary:
cncsimulator.exe.
Need our current domain/IP allowlist? Contact support and we’ll provide the latest details for your environment.
Still stuck? Send us this
Email support@cncsimulator.com with:
Subject: Cannot connect to server at start-up
License ID: <paste from Copy to clipboard>
CNC Simulator Pro version / Windows version: <e.g., 4.0.1.4 / Windows 11 23H2>
Network type: <home / school / corporate / VPN>
Proxy/VPN: <none / details>
What I tried: <hotspot test / firewall allow / proxy set / time fixed>
Exact error text or screenshot: <paste or attach>
PowerShell test results (optional): <Test-NetConnection output>
Bottom line: This message indicates a network path problem. Allow outbound HTTP to our services (and configure proxy if required), ensure time is correct, and try a hotspot to confirm. If it still fails, send us the details above and we’ll pinpoint the block quickly.