I get "Connect timed out" when trying to send a file.

This means the sending machine could not reach the receiver's TCP port within 5 seconds. The most common cause is Windows Firewall on the receiving machine blocking inbound connections.

Fix it:

1. On the receiving machine, go to Settings > Add Firewall Rule. This creates the correct Windows Firewall exception automatically.
2. Try the transfer again.

If it still fails, check for third-party firewall or endpoint security software on the receiving machine that may be blocking inbound TCP connections on ports 41235-41245.