Tones Sync in iTunes Failed with Message the Item could not be copied because it was not found

Hi All,

I am using IPhone 5s with iOS 10.3.1, using itunes 12.5.5 on Windows 7 SP 1 (Version 7601)

I have created the ringtone through itunes following the procedure of converting song to AAC file, changing extension from m4a to m4r, song length 28 Seconds. Also added to tones, played it on the itunes. but when i try to sync the tones to my iphone then the message comes that "The Item" could not be copied to iphone because it was not found. What should I do Now.