[T-Mobile, Samsung Galaxy SIII] DJ_SpaRky:
I am running the d2tmo builds on my T999L without issue, the Asserts are for the bootloader and not the device, T999LUVAMB7 vs d2ltetmo/d2tmo. They are already there for MB7 bootloader.

In the ROM cm-10.1.3-RC1-d2tmo.zip under \META-INF\com\google\android\updater-script:

assert(getprop("ro.product.device") == "d2tmo" || getprop("ro.build.product") == "d2tmo");
assert(getprop("ro.bootloader") == "T999UVDLJA" ||
getprop("ro.bootloader") == "T999UVDLJC" ||
getprop("ro.bootloader") == "T999UVDMD5" ||
getprop("ro.bootloader") == "T999VVLDLL1" ||
getprop("ro.bootloader") == "T999LUVAMB7" ||
getprop("ro.bootloader") == "T999VVLDMF2");

The T999L one is there. Try updating your CWM or switching to TWRP for d2tmo (what I use). Might be an issue with the recovery not liking the script.

Also, could you have the T999N from MetroPCS? it has a different baseband/bootloader, but still has LTE, I don't believe that there are Asserts for that bootloader yet.

---------- Post added at 01:48 PM ---------- Previous post was at 01:36 PM ----------

Here is a Guide that I had built a while ago, I have updated it for the 10.1 RC series and 10.2 Nightly builds.

Enjoy! :highfive:

Custom Recovery and CM10.1.x RC or 10.2 Nightly Installation Flash Processes:

Items needed:

Galaxy S III 4G LTE T999L (of course)

Custom Recovery; TWRP recommended, CWM or CWM Touch optional

Micro USB to USB cable (or other means to transfer files off of and onto device)

Files:

CyanogenMod CM10.1.x RC or CM10.2 Nightly ROM file for d2tmo

GApps for ROM Version(4.2.2 or 4.3)

SuperSU Flashable zip (optional)

Recovery install process:

1. Download and install USB Drivers from here: Thanks to [MENTION=4081205]DocHoliday77[/MENTION] for hosting

http://www.androidfilehost.com/?a=show&w=files&flid=1368

2. Download and extract ODIN 3.07 from here: Thanks to [MENTION=4081205]DocHoliday77[/MENTION] for hosting

http://www.androidfilehost.com/?a=show&w=files&flid=1369

3. Download TWRP 2.4.4.0 or 2.5.0.0 recovery image (.tar file) from here: Thanks to [MENTION=4081205]DocHoliday77[/MENTION] for hosting

http://www.androidfilehost.com/?a=show&w=files&flid=5155

4. Save all open files and reboot computer

5. Boot phone into Download mode (also called ODIN mode) by shutting down the phone and holding Vol Down & Home then pressing Power until it vibrates, still holding Vol Down & Home buttons, until the "Yellow Triangle" screen shows up.

6. Plug phone into computer and open ODIN 3.07 and make sure that only "Auto Reboot" and "F. Reset Time" are checked.

7. Click on the "PDA" button (right side about half-way down), browse for TWRP .tar file, click "Open" button.

8. Click "Start" button and watch to "Reset" or "Fail" to show in the 1st square (upper left side)

9. Phone will reboot, then power down and boot into recovery by shutting down the phone and holding Vol Up & Home then pressing Power until it vibrates, still holding Vol Up & Home buttons, until the blue "TeamWin" screen shows up.

10. Enjoy your Team Win Recovery Project custom recovery on your Samsung Galaxy S III 4G LTE SGH-T999L (d2ltetmo)

11. Profit!!

CM10.1.x Release Candidate Installation Flash Process:

1. Download latest CM10.1.x RC from this page: Thanks to [MENTION=4193338]CyanogenMod[/MENTION] team for everything that they do.

http://get.cm/?device=d2tmo&type=RC

2. Download Gapps for CM10.1 (4.2.2) from this page: Thanks to [MENTION=4193338]CyanogenMod[/MENTION] team for everything that they do.

http://wiki.cyanogenmod.org/w/Gapps

2.5. Download SuperSu flashable zip from this page: Thanks to [MENTION=631273]Chainfire[/MENTION] for hosting. (optional)

http://xdaforums.com/showthread.php?t=1538053

3. Backup everything, using TitaniumBackup, Carbon or similar

4. Backup everything, using Nandroid via recovery (TWRP, CWM or CWM Touch)

5. Copy Backup files off of device on to PC or HDD for safe keeping.

6. Copy contents of /sdcard (and /extsdcard, if desired) to same PC or HDD (just in case)

7. Copy ROM, GApps & SuperSU (optional) to /sdcard or /extsdcard

8. Reboot into TWRP Recovery

9. Wipe Dalvik and Cache

10. Wipe Data (this will ERASE all settings and user apps, anything not in /system or /sdcard)

11. Wipe System (this will ERASE the operating system, phone will be unusable until a new one is installed)

12. Wipe Dalvik and Cache again, just to make sure

13. Reboot into TWRP Recovery

14. Install ROM, GApps & SuperSU from /sdcard or /extsdcard

15. Wipe Dalvik and Cache again (YES, again)

16. Reboot System

17. Watch for CyanogenMod boot animation and then initial setup to appear. **DO NOT TOUCH PHONE**

18. Wait at least 10-15 minutes for all of the one-time setup scripts to run and everything to settle into place.

19. Reboot System

20. Watch for CyanogenMod boot animation and then initial setup to appear.

21. Wait for at least 5 minutes for everything to settle into place and run through setup

22. Enjoy your new CyanogenMod CM10.1.x RC ROM on your Samsung Galaxy S III 4G LTE SGH-T999L (d2ltetmo)

23. Profit!!

CM10.2 Nightly Installation Flash Process:

1. Download latest CM10.2 Nightly from this page: Thanks to [MENTION=4193338]CyanogenMod[/MENTION] team for everything that they do.

http://get.cm/?device=d2tmo&type=nightly

2. Download Gapps for CM10.2 (4.3) from this page: Thanks to [MENTION=4193338]CyanogenMod[/MENTION] team for everything that they do.

http://wiki.cyanogenmod.org/w/Gapps

2.5. Download SuperSu flashable zip from this page: Thanks to [MENTION=631273]Chainfire[/MENTION] for hosting. (optional)

http://xdaforums.com/showthread.php?t=1538053

3. Backup everything, using TitaniumBackup, Carbon or similar

4. Backup everything, using Nandroid via recovery (TWRP, CWM or CWM Touch)

5. Copy Backup files off of device on to PC or HDD for safe keeping.

6. Copy contents of /sdcard (and /extsdcard, if desired) to same PC or HDD (just in case)

7. Copy ROM, GApps & SuperSU (optional) to /sdcard or /extsdcard

8. Reboot into TWRP Recovery

9. Wipe Dalvik and Cache

10. Wipe Data (this will ERASE all settings and user apps, anything not in /system or /sdcard)

11. Wipe System (this will ERASE the operating system, phone will be unusable until a new one is installed)

12. Wipe Dalvik and Cache again, just to make sure

13. Reboot into TWRP Recovery

14. Install ROM, GApps & SuperSU from /sdcard or /extsdcard

15. Wipe Dalvik and Cache again (YES, again)

16. Reboot System

17. Watch for CyanogenMod boot animation and then initial setup to appear. **DO NOT TOUCH PHONE**

18. Wait at least 10-15 minutes for all of the one-time setup scripts to run and everything to settle into place.

19. Reboot System

20. Watch for CyanogenMod boot animation and then initial setup to appear.

21. Wait for at least 5 minutes for everything to settle into place and run through setup

22. Enjoy your new CyanogenMod CM10.2 Nightly ROM on your Samsung Galaxy S III 4G LTE SGH-T999L (d2ltetmo)

23. Profit!!