A few moments ago I tried to post a new entry for my blog, and found that the password was being denied.
What I needed to do was log into my google account, and the go to the security settings, and change the account permissions, particularly the access for less secure apps:
Changing this to enabled allowed it to work again.
Today, I was called out to a client who reported that their backups were failing. They just use the standard Windows 7 backup, but after getting about 30% of the way through, the backup failed with the above error.
It turns out the problem was caused by the anti-virus software detecting a virus (some Java exploit) during the backup, and causing it to fail. The virus was being reported in Microsoft Security Essentials in a shadow copy on the disk.
So, my solution, was first, clean the account that was infected using Security Essentials. That would probably be sufficient to let the backup complete, but I also took the following additional steps, just to be certain nothing was hanging around in a previous snapshot:
After deleting, your disk should no longer contain any copies of the file security essentials is complaining about, and backups should be able to proceed as normal.
