To view the diagnostics on your device, open Todo Settings > Information > Diagnostics UI under the Synchronization Log section you will see an error message like this:

When Todo's diagnostics is reporting the "parseXMLFileAtURL returned error: timed out" error while attempting to connect Todo with Appigo Sync or just syncing from Todo, the issue is because Todo is unable to communication with Appigo Sync. The two common reasons for this failure are do to Todo and Appigo Sync are not on the same network or a firewall is blocking the incoming Todo traffic from reaching Appigo Sync. Please check your firewall setup and make sure that Appigo Sync is allowed to receive incoming requests.

There other less frequent and more advanced configuration setup that causes this error is when Todo has been configured manually with an incorrect IP address and / or port for Appigo Sync. To resolve this issue please verify that Todo is configured with the correct IP and port for Appigo Sync.