S4 GT-I9506 is stuck on Firmware upgrade encountered an issue

this model seems difficult (gt-i9506)

i tried to root it via towelroot, then kingoroot, these failed but then now the reboot is stuck on "firmware upgrade encountered an issue"

ive tried Kies firmware recovery but the download fails after 80%,

ive tried the sammobile download the ROM this too fails, network drops out tried this 3 times

i want to try Kies emergency recovery but cant find any recovery code

im stuck i dont know what to do now been researching for 4 hours cant find solution :crying:

Firmware upgrade encountered an issue !!!!! please help

I have Gear S TMobile version (R750T) .. I was trying to flash stock firmware (R750TUVU1AOA7_R750TTMB1AOA7_TMB) but is stopped and gave me this message

Firmware upgrade encountered an issue
Please select recovery mode in kies and try again


tried kies with no luck ... trying to connection :crying::crying::crying:


any hope ???

Galaxy Grand Duos GT-I9082 running CM12 Firmware encountered an issue

My Galaxy Grand Duos GT-I9082 was running the Cyanogen Mod 12 for the past 4-5 months and over a period of time the system started crashing frequently and I wanted to get back to the Stock ROM. I made a factory reset, wiped partitions and wiped delvik cache. I started Odin, got the device into downloading mode and flashed the Stock ROM (downloaded from sammobile 1 year ago) which I have flashed several times before also and which has worked absolutely fine everytime. This time however, after I flashed the Stock ROM, the downloading process started and the process came to a halt after a few moments and the operation "FAILED". I made a reset and tried to flash the Stock ROM file again but to the same result. I made an exit from the Odin, disconnected the device and tried to start it but it said "Firmware upgrade encountered an issue. Please select recovery mode in Kies & try again."
Neither can I start the device nor can I go into recovery mode. The phone can only go into the downloading mode right now.
I downloaded other Stock ROMs and tried flashing them but none of them are working. I even tried the emergency recovery in Samsung Kies but that does not recognize my device itself.

Anyone has a solution here?