HTC One Mini not making calls

[AC Question]

I have an HTC One Mini and It recently prompted me to update a new software version so it now runs on Android 4.4.2. This update was about a couple weeks prior to the phone giving me an issue with calls. I can't get an outgoing call completed because it stays in the calling screen until the call eventualy hangs up itself. When I receive calls, I can answer but I cant hear the person on the other end and when I press the end button, it takes a few seconds before it hangs up the call. I have already tried soft and hard resets, but the same issue came back..

 

[B. Diddy]

Welcome to Android Central! Try booting into Safe Mode, which disables all 3rd party apps. If the problem goes away, then something you installed is interfering--the challenge is to figure out which app. You may have to uninstall apps one by one. If the problem persists in Safe Mode, then there's something wrong with the firmware. Steps for Safe Mode are at the bottom of this article: Reset: HTC One (LTE) | T-Mobile Support

You could also consider booting into recovery and wiping the cache partition (also described in that article). This can help with a variety of issues, especially after a system update, and won't erase any personal data.