Dotted circle on songs or ringtones...
Honestly,
After ALL these years iTunes/iPhone users are STILL encountering the same bug (there is NO other name for this), which can only be fixed by backing up and setting up as new device the ENTIRE phone...
This workaround is like killing a mosquito with an A-bomb and I cannot believe no one has come up with a simpler and quicker solution to it (or why it even happens). So, firmly believing the real and straightforward solution is out there, I'll be waiting for it right here... :)
iPhone 6