Before even trying anything, I would suggest that you backup your current EFS partition first.
You can do this from within the custom TWRP recovery menu, using adb commands or possibly some apps or PC programs. You may need root for some methods. You can also copy the EFS folder files with a root type explorer.
Once you've made a backup (in case you make things worse), this thread here may be of help :
edit: yes, I know it's for the the sgs2, but the dev does say other devices too.
Also, have your tried to reflash manually your firmware with Odin?
There are guides here in xda and our forum, and firmware can be found at sammobile.com or samsung-updates.com
As last resort, I'd take a look at some of the sgs2 EFS repair apps. Could make things worse, but also fix it. https://play.google.com/store/apps/d...gtoolbox&hl=en
Any decision is ultimately up to you....
Edit 2: if all methods you try are unsuccessful (or made worse and totally unrecoverable), you may have to send to Samsung for repair. Sending to an owner of a RIFF box (JTAG repair) may be faster and cheaper though.
Best of luck
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