One user can't access ReadyNAS from iphone

I have a readyNAS 204.  I am using it for backing up iphone photos.  One user can do so without any issues. But, the 2nd user, when she accesses readyNAS from iphone, she gets: "Unexpected response from server".  She can log into Netgear app on her iphone without any issues. She gets the ReadyNAS icon. But, any attempt to access it gives the above error message. Nothing shows up in logs.  I am running the latest firmware 6.9.2.  Any help would be appreciated.