Failed connections are the most common issue, and the cause is almost always one of five things: the device is offline, accounts differ, the network is restricted, the access code is wrong, or a session is already running. Work through them in order and most cases resolve in minutes.
Check device status first
Confirm on the controlling side that the device shows as online. If it is offline, the client is not running or has no network — check start-on-boot, connectivity and sign-in state on the device.
- The device is powered on and not asleep
- The client is running and signed in
- The network works (it can browse normally)
- Check last seen time to judge how long it has been down
Then accounts and permissions
Both ends must use the same account, or the device must be shared with you. A password error means the access code was typed incorrectly or has been changed.
- Same account signed in on both ends
- The device is shared with your account
- The access code was entered correctly
- No time-window restriction applies
Finally network and software
Corporate networks, firewalls and security suites can block outbound traffic. Try a phone hotspot, or whitelist the client in the firewall and security software.
- Try another network such as a phone hotspot
- Whitelist the client in the firewall
- Disable security software briefly to confirm blocking
- Make sure outbound port 443 is allowed
FAQ
It says offline but the computer is on.
Usually the client is not running, was killed by security software, or the system went to sleep. Check start-on-boot and power settings.
It hangs on "establishing connection".
Most often the network is blocked. Try another network; if both ends sit behind strict networks, review proxy and firewall policy.