Share your experience!
I've had my Sony Xperia X for a few months and it's has worked fine since I've had it with every pair of headphones I have (one of which is a Sony pair) and it also worked via the Aux in my car. Suddenly it will not work with any device and I keep getting the message "Headset not supported..."
I've googled it and many forums suggest it's an issue with Smart Connect but that's not inastalled on my phone.
I did see another post relating to this topic from December but it was never resolved.
Any ideas before I post it back for repair/replacement?
Since this happened after an update maybe you should try reinstalling the firmware by running a software repair using Xperia Companion.