[Sprint HTC EVO 4G LTE] Talamor:
EDIT: 11:15pm 9/25/2012 - ISSUE RESOLVED, SEE BOTTOM OF POST FOR SOLUTION

Okay, relevant information first:

Evo 4G LTE on Sprint

HBOOT 1.15 S-ON HTC DevUnlock

Current ROM CM10 Nightlies

Sprint-Google Voice integrated number

Now for the issue:

Texts can not be sent through the messaging app. When attempting to send a text, it will say "sending..." for a few seconds, then I get a notification saying "message not sent". Clicking on this notification takes me to the messaging app where the failed message has a red triangle next to it. When I long press the failed message, it comes up with a menu, and when I click "view details" it says "Error Code 98".

This happens both when connected to WiFi and when not connected to WiFi. It also happens both in my home town, and another town 45 minutes away (meaning the issue doesn't seem to be with the particular tower).

The last successful text sent or received was on Sept 13th.

Calls still operate as normal.

No changes were made by me between when my SMS was working properly, and when it stopped working. (Same ROM, Recovery, Kernel, etc). I haven't downloaded any SMS apps (handscent, gosms, etc) that could be interfering with the messaging app. I DO have the Google Voice app, but I had that when SMS was working properly as well, and the GV app hasn't been updated since March (meaning it shouldn't have changed how it was behaving).

Other peculiar behavior:

In addition to not being able to send texts via the messaging app, it seems that my number is also unable to receive texts. When texts are sent to my number, my phone does not receive them and they also do not show up in my Google Voice inbox. The sender is given no notice that the text has not been received. I am able to send texts from the Google Voice app, and others successfully receive them. When I send a text to myself from the Google Voice app, I receive it in my Google Voice app, but not in the stock messaging app (even though my Google Voice app settings say that texts will be received via the messaging app).

Things I've Tried (Updated: 3pm EST, 9/25/2012 ):

* Turning it off and on again

* Updating CM10

* Changing Google Voice settings (though it's possible I overlooked a setting)

* Factory Reset, Reflash ROM

* Flash Sense ROM, Update Profile/PRL

* Flash different AOSP ROM (Paranoid Android)

Things I've Not Tried (in order of how willing I am to do the things):

* Using an alternate SMS app (GoSMS, Handscent, etc)

* Un-integrating (and Re-integrating) Google Voice

* Giving the EvoLTE a relaxing bubble bath, to calm it down

* Flash Stock, Unroot, Update Radio

So, does anyone know what might cause this problem, and/or how to resolve it?

EDIT: Solution below

STORY:

I called Sprint Support, and had them reactivate my old phone (Evo4G running a CM9 alpha), by giving them the MEID for that phone. At this point I powered the phone back on, and called an activation number that they had given me (888-546-0314). On a Sense ROM, I would have simply updated my profile, instead of calling the number. We then tried SMS on the reactivated phone, and it worked (also, texts began showing up in Google Voice again at this time). I turned off my Evo 4G LTE, then I gave him the MEID for it and had him switch my number back to that phone. After he said he had switched it, I powered the Evo 4G LTE back up, and updated the profile, which I was able to do since I was still on Viper4G (note: I had to update the profile via WiFi, it might have worked over data, but it was taking longer than expected so we cancelled and just use WiFi for the update). Once the profile had updated, I called the test number again to confirm that the phone was activated. When I tried SMS, it worked as it should, including sending a copy to Google Voice.

TL;DR:

1. Find an old phone

2. Write down the MEID of both phones

3. Find a third phone to use to call Sprint (since you'll be activating/deactivating the other phones throughout the call)

4. Call Sprint Customer Support (888-211-4727), and punch the appropriate numbers until you are talking to someone

5. Have them switch your number to the old phone's MEID. Make sure the old phone is activated.

6. Have them switch your number back to the new phone's MEID. Make sure the new phone is activated.

7. Texting should be working on your new phone again.

Notes: The old phone may not be necessary. It may be enough for the Sprint Service Rep to deactivate your phone and then reactivate it. But I figured I would write out the EXACT method that solved the problem for me, since I am positive that this method has worked at least once. I have neither the means nor the desire to recreate the problem, so I will have to leave testing of other methods to the next person that experiences this problem.