Now, today I tried to do exactly the same with another ls980 (zva, stock rom) but for whatever reason I can't copy apns-conf.xml in /etc/.
So yes, I'm rooted ! (at least root checker says im rooted)
I tried ##3424# Enable diag mode, not better !
Usb debugging is on !
So I don't know why I don't have permissions..
Totalcommander gives me an error on transfer and I cannot edit, rename or remove any files in /etc/
Es filer explorer (allowed in supersu) tells me permission denied
any ideas ?