Could not sync - connection was reset (iPhone 7)

Recently, I often receive the following message when I perform a manual backup of my iPhone 7, iOS 10.2, (from iTunes on my iMac (MacOS Sierra) (iTunes 12.5.4.42).

"The iPhone ... could not be synced because the connection to the iPhone was reset".

In fact, the backup stalls for a number of minutes before the message appears.

The backup appears to fail since the date and time of the "last backup to this computer" are not updated.

However, if I disconnect the iPhone from iTunes and reconnect it to the iMac, iTunes shows that the backup completed (i.e., the correct date and time appear as the last backup to the computer).

Tom - I have performed your recommended steps and tried a backup and the error message did not appear; the backup completed as expected.

I hope this is a permanent fix for this annoying problem. Time will tell.

Thanks!

I occasionally see this problem as well. (iPhone 6+/iOS 10.2.1/iTunes 12.5.5)

I do manual backups, and that message appears, though the backup was actually performed. I think it's just an erroneous glitch.

iTunes sets the lowest bar for Apple software QA, and overall, the quality of Apple software has seldom been lower (you can tell from my name how long I've been a user).

I'm having the exact same problem. I noticed this about three weeks ago. You are correct if you close iTunes and come back it looks like the back up is working but I am not sure why getting the alert. Also concerned the back up is not full

I also have this problem. Started a few weeks ago.

Anyone found a solution?