Solution that worked for me and info on a few other options
I just survived the imei null/no baseband ritual many of us suspiciously had to go through with the UFNG2 update.
Nandroid backup got corrupted after external hdd got corrupted which made the softbrick experience that much more fun
and all my EFS backups were damaged or gone. .
-The UGNG1 update fixed this particular problem for me (and introduced me to bluetooth issues this time around).
* Reflashing modem with modem.bin file before the update didn't help.
* Neither did flashing with the latest modem files which gave me a binary error.
But perhaps you will have better luck like others so check this thread http://forum.xda-developers.com/gala...odems-t2842806
to find the files.
* The Efs professional tool could not connect to the phone due to COM being inaccessible.
When flashing stockfirmwares and the modem odin would also display error message in regards to this.
Do check it out thouhttp://forum.xda-developers.com/gala...ional-t1308546
After too many hours wasted only QPST v2.7 Build 4.11 seemed to overcome the Locked/inaccessible com problem
It accessed it and i could see it in the device manager of windows so after hours and hours of getting no where this seemed like my best bet.
But then the firmware news reached me and i went for the more familiar way.
£ when flashing the NG1 firmware i also added the HOS and modem file in odin (CSC).
The error message regarding locked com appeared in the odin log.
I assume that happened because odin first flashed the mobile.bin i added in CSC before the firmware file got to it.
So the NG1 firmware update saved my life as it removed residual buginess from the firmware flashing to get out of softbrick.
But at the same time i truelly regret ever upgrading from android 4.3 and do not recommend it due to other issues popping up
and frankly i see no REAL improvements or changes that are worth the trouble.
Best of luck!