Ringtone volume setting grayed out

[Ikomz]

I have a Z3 Compact with Android 5.1.1. The problem is that I cannot change the volume of the ringtone. I don't have any other sound issues. As you can see from the screenshot, the ringtone volume setting is grayed out. Any idea of what could be wrong?

[rowyourboat]

So if I am erasing all internal memory, how do protect all the documents and files I want to keep.
In the second paragraph, how do your directions apply to what I am doing? Am I meant to be turning phone off and taking the SIM card out before starting PC companion?

[rowyourboat]

Sony PC companion file won't open as well

[_alexdon_]

Just start the repair process, all the steps are given there. Why PCC won't open?

[sanwi]

I had thé same problem, restoring the factory settings worked but I lost most of my data... (not the photos though). But it happened several times (this is the fourth), is there was another way that does not include resetting the phone?

[El-Cid]

This was the solution for me as well:

"My phone was on do not disturb, when I cancelled that the slider moved again... Hope it helps somebody"

locate the "do not disturb" setting and disable it.