[Verizon Galaxy Note 4 Q&A, Help & Troubleshooting] BeckPC:
DON'T PANIC!

I own two Verizon note 4 devices. You could call me a flash-a-holic. I love this stuff and really love my Note 4. It's the best phone I've ever seen with great features that many newer ones do not have. However, you already know that ... so I'll dispense with the speech. Before any of you think I'm new to this stuff, I should say I've been flashing devices since 2005 with my old Windows Mobile devices. I also manage a total of seven Note 4 devices from Verizon, five of which are on my own plan. My neighbor has the other two because they loved mine so much.

Recently, I've been playing around with some of the International ROMS, particularly the Note 7 and S8 ports in the Snapdragon section. I really love those for the scrolling snapshots and S8 launcher (even though I use Nova on my daily device). However, after flashing so many of those and having to use a variety of data fixes to get 4G working, I seemed to have messed up my device. I was having really odd issues, like going from 1X, 3G, 4G, to disabled for several minutes before it would settle and finally connect. I also had issues with text messaging. It would work fine, for a while. Then it stopped receiving messages, but I could still send. I messed with APN settings, which didn't help. I flashed more data fixes and APN fixes I found. Nothing really fixed it. So I figured it was the SIM card. I went to Verizon and admitted it was a custom ROM, but he could see that obviously. He gave me a new SIM card, yet I still had the same trouble. After a reboot, it wouldn't settle on a connection for about three minutes, sometimes more. I still was unable to receive text messages (including MMS) on that device. Even a Nandroid backup did not fix the problem.

Here's what I did to fix it.

I decided it was probably best for me to restore back to stock and go through the rooting process again. Ugh... but I love my phones. I'd do anything to keep them going. Instead of using ODIN to restore back to the original stock, I used the Safe Upgrade for 6.0.1 found below. It's been fixed so it does not lock the bootloader again, but restores everything else to stock, but you get to keep TWRP recovery.

https://xdaforums.com/note-4-verizon/development/firmware-safe-upgrade-to-marshmallow-t3402727

I let it boot and go through the process (without signing into anything). Immediately, I realized that my data/4G problems went away. It never flickered even once. I let it sit for 15 minutes once it finished it's initial setup and rebooted back into RECOVERY to flash Kevin's Flashpoint kernel. That gave me root again with Magisk. After a full reboot, I then went into DOWNLOAD MODE and flashed the newest modem (CQI2) using ODIN. Then it was time to settle on a ROM for my use. This time I decided to go back to another International ROM and it appears I'm good to go. Just remember, the Verizon Voicemail app won't be included and usually won't work with an International ROM. I've tried and only was able to get it to work on one of them. It runs, but just will not connect to Verizon properly to access your voicemail. I'd love to find a real fix for that.

Ah... it's good to be working again. Now I can use Titanium Backup to restore my apps and data. BUT I DO NOT RECOMMEND RESTORING SYSTEM DATA. It can only cause problems.

Just a few suggestions for anyone having issues. ALWAYS keep several files on your PC/Device for this type of recovery.

1. Keep the Safe Upgrade to Marshmallow 6.0.1. image. It will be your lifesaver in case something goes wrong.

2. Keep a good working kernel (of your choosing). I prefer [MENTION=5285430]kevintm78[/MENTION] Flashpoint Kernel. It restores Magisk v14 and almost always passes SafetyNet. I keep both stock and port versions on hand (just in case).

3. Keep a good ROM or two (also of your choosing) in order to reinstall a ROM you prefer to use.

4. Keep a working data fix to flash if you're using one of the ported ROMs. Not all are created equal, nor the same at all. Not all of them work. I recommend the Aurora N7 Data fix (Alpha 5 for my N910V): https://xdaforums.com/showpost.php?p=69066109&postcount=2681

5. Keep the latest version of ODIN around. You'll need it from time to time.

Last but not least ... try this fix before you start blowing up the forums with questions and complaints about problems you have. I've found that most of the odd problems people experience are caused by using Titanium Backup to restore system settings created from another ROM, or trying to add different mods, which cause issues. Don't blame the developer for issues that you have that no one else has reported. Most likely, it has nothing to do with their software. It's probably something you installed or restored from a previous backup. You can let those old text messages and phone history go.

If you use Titanium Backup, only store system data IF you are using the exact same ROM as before. Otherwise you will experience problems.

I was sure my Note 4 was ready for disposal after the cellular issues I was experiencing. However I'm happy to report it's good as gold now. I'm not sure how much longer these devices will work for us, but I'll never freely get rid of mine. Besides, who else can fix the TV in the bar when the bartender loses the remote? Not very many devices these days have IR Blasters installed. I've used mine at least a hundred times for that very reason. But that's only one reason for loving this device. I could go on, but you already know that Samsung made the best device with the Note 4 models.

I hope this info helps anyone having problems after flashing so many different ROMs. I know, it's hard to settle on only one. Happy flashing and remember ... DON'T PANIC!