This error message occurs when a Wi-Fi connection cannot be made between the camera and smartphone. Please check the following.
* Is the camera in sleep mode?
The Wi-Fi connection is disconnected in sleep mode. Therefore, wake the camera up from sleep mode and reconnect the Wi-Fi.
Press the camera shutter button > select the smartphone "Settings" > turn Wi-Fi on > tap "THETA******" in the network selection > start the app.
* It may be difficult to connect to Wi-Fi for some reason. Turn the camera's Wi-Fi button off/on, and then connect to the Wi-Fi again from the setting screen.