Ringtone changed by default without changing it

[amit_verma0033]

Hi Can anyone help me out that why my ringtone is changed by default as I am not changing it. I have gone through all setting but this problem is not sorted out. The default ringtone is changed to none due to this I am not able to pickup important calls . Please help me.

[ZT-7281f0b7]

Try clearing cache partition !!

[nguyen_duyky]

This may happen after you have just updated your phone. If it happens randomly then that is the error.