Hi! I am also a verizon customer, and I also own an HTC One M9. On April 17-20 (sometime in there) I had the exact same issues with my device. My home screens were all set back to default, my contacts were all gone, my old messages were all gone, ringtones and alarms all set to default, and my Verizon Voicemail application had disappeared.

Here's the kicker: if your name refers to Reynoldsburg, Ohio, we bought our phones from the same store (the one off of route 256 near target). I haven't found anyone else with this issue online anywhere.

Keep me updated on any progress you've made! It seems like all the old files are still on my phone, it just doesn't know where to look to find them. My music is still there, and my old downloads are still there.

Seems very odd.