Every button on the front has become unresponsive. I replaced cars a few months ago but unit has been working fine since. The touch screen is working perfectly. Any ideas? Thanks.

When all else fails, try a hard boot (disconnect the car battery for ~30 seconds).

Then, the first time you turn on the ignition, hold the eject button while turning the key, Continue holding for 5 seconds. This is to see if the problem is hardware or software related. If the screen doesn't open - it is likely a hardware issue. Regardless, if the buttons aren't working you won't be able to try any software fixes anyway. In that case - you'll need to send the HU in for repairs.

However, if it does open maybe you can get into TestMode. You can find many threads already on TestMode, so I won't repeat it here. But you need to have working hard-buttons to do anything in Testmode. If your buttons work in testmode, then it sounds like a software (system or app) problem after you boot into Windows CE (or Pioneer app software). We might be able to help if it is - but will need feedback on the above first.