Looking for logging into the Sms Backup Error site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Sms Backup Error site. After that you can login as usual with your login credentials.
https://forums.androidcentral.com/ask-question/915764-sms-backup-login-error.html
https://github.com/jberkel/sms-backup-plus/issues/554
https://github.com/jberkel/sms-backup-plus/issues/762
https://github.com/jberkel/sms-backup-plus/issues/184
https://github.com/AbinashBishoyi/android-sms/issues/65
https://plus.google.com/communities/113290889178902750997
https://support.cloudhq.net/how-to-troubleshoot-authorization-with-gmail-failed-error/
https://play.google.com/store/apps/details?id=com.zegoggles.smssync
http://www.droidforums.net/threads/problem-with-sms-backup-by-christoph-studer.32643/
http://www.droidxforums.com/forum/droid-x-help/8225-sms-backup-problem.html
https://techfleece.com/2013/08/01/how-to-backup-your-text-messages-to-gmail-using-sms-backup-for-android/
https://androidforums.com/threads/issues-with-sms-backup-and-backup-to-gmail.232373/
https://support.agleader.com/kbp/index.php?View=entry&EntryID=1707