Unsupported Browser Message
I'm running OS X Yosemite v.10.10.5, and Safari is v. 8.0.8, my wife and each have our own separate logins. This issue is affecting her side only. When logging into iCloud.com or Youtube.com she gets the message "unsupported browser: please update to the newest version of Safari, etc.). It's slowly driving me crazy as I've tried everything I can think of, but can't seem to fix the message. I disabled plugins, I disabled extensions, I've rebooted, etc. Any ideas would be much appreciated. Again, on my side of the computer, everything is exactly the same as her, but I do not get the error message. I'm assuming the cause has to lie in her User files, but not sure where to begin.
Thanks!
iMac, OS X Yosemite (10.10.5), Safari 8.0.8