One of the following points can be the cause for the log in issue:
1. No internet connectivity. Please check if you are connected to a Wi-Fi network with internet connection or if you are connected to 3G or 4G (check the network signal on the top right of the screen - there should be a H+ or 4G symbol there);
2. Time and date of the device is incorrect and it is not being set automatically;
3. The device does not have the latest version of eCrew installed.
If all of the above is correct and you are still facing the issue, please create query. Thank you.