It would be really helpful if you’d provide the following information so our engineer colleagues can identify and solve your problem sooner.
Which device has the problem? Viewer or Camera both
Device Model Name: huawei y7 pro and Asus zenfone
OS Version: 8.0
AppVersion: 3.16.3 (build1692)
I have just installed the latest update and can’t sign in on both the viewer and camera phone. Have signed out and in again. Have Uninstalled and reinstalled. Have updated Google play service version. Have turned off WiFi then on again. Have checked username and password … Still can’t sign in… Very frustrating