Thank you for your post regarding your issues with your device. From just reading your post, it seems that there is software instability with your device. This could be caused by an application that has been downloaded or that may have become unstable. Visiting a service and repair center can help determine the root cause of the issues you are experiencing. They will place your device on a machine and run various test that will let them know if it is hardware or software.
Wow, is it rooted? I've had my EVO since it was released and that has NEVER happen, you rooted it, didn't you? Whoa, dude don't root your phone. Rooting leads to UNFORSIGHNED, unsupported problems. Why bother. Just enjoy the experience.
I had this exact problem, and after dealing with it since the phone update that borked all of my custom ringtones, I did a factory reset.
My phone was never rooted, however, I am more inclined to now that this happened, only because if I had bothered too like I did on the older EVO 4g, I would have been able to roll back the update with a custom backup.
Not being able to make a call for several minutes, open a text message to reply for minutes on end if at all and never being able to open a voicemail from someone who literally just called? I call any one of those things reason enough to root your phone, let alone having all of them happen day after day after a "Legitimate" phone update, with no fix in sight.
I am honestly upset with the EVO LTE, and will probably be moving on to Samsung over HTC because of this, which sucks because I was genuinely excited to own this phone. Kind of hard to "Just enjoy the experience" when I loose all of the basic functionality I paid for.
To answer why this happened, I'm sure it had to do with getting the "Ringtone Picker App" fix that came out a little bit after the update that screwed up all of the phones out there.
I agree with Markie_B, sounds like you have an issue with the 3rd party apps installed. There are a couple things you can try,
Boot to Safe Mode. Reboot phone and at the first white boot screen, press the Volume Down button until fully booted. You will see Safe Mode in the bottom left corner. Then use the phoen as normally as you can. This in a sense prevents 3rd party apps from loading during startup. If the phone begins to function properly, then most likley a 3rd party app or apps are wreaking havoc within the phone. So you would need to start uninstalling apps to narrow down the problem app or apps.
Most people opt to perform a Hard Reset as there tend to be a lot of apps installed.
Another option is to visit a repair center. Keep in mind, they will perform a Hard Reset as standard procedure.
A Hard Reset isn't that bad as long as you have all your contacts, calenders, etc.. synced with Google and your photos and videos synced with some cloud service. About the only thing you lose is app information and personal customizations to the desktop
As others have said it's probable a 3rd party app like Handsent messaging or something.I have had the phone from day one and never had this happen take it in or do the reset.