This error is most associated with network firewall issues. If you get this error you can try these items
- Try logging in on a different wifi network
- Try restarting your device
- Whitelist our servers. Here is a short article https://mergemobile.zendesk.com/hc/en-us/articles/210669983-Email-Delivery-and-FTP-SFTP-Troubleshooting
- If your device is corporate issued, you may have a VPN setup on your device. You can check to see if you have a VPN by going to your device settings -> General -> VPN. If you do have a VPN setup on your device then you will need to contact your corporate IT administrator and talk to them about Whitelisting our servers https://mergemobile.zendesk.com/hc/en-us/articles/210669983-Email-Delivery-and-FTP-SFTP-Troubleshooting
If you continue having issues with this error even after trying the above items, please email fastfieldsupport@mergemobile.com