I used the below guide to update my router it was successful only one problem. I did not have a sim in the unit when I installed the firmware upgrade now every time I put a sim in the router I does a boot loop for 4-5 times then shuts down. I cannot boot the router or turn it on without removing the battery power. If no sim I can log in 192.1681.1 and see or make changes just cannot boot with sim.

Currently my router shows Firmware upgrade: NTG9X50C_10250101

APN changed for ATT to Telstrainternet

is there any newer firmware or solutions available that I can fix this issue?

I used the following info below to upgrade

Firmware LINK:

https://www.dropbox.com/s/s27ftyfjpvn9819/fdt.exe?dl=0

:MR1100 Firmware Update

Download the newest generic firmware from the Netgear support site for your country (the routers country).
Download FDT.exe version 4.6.2.0. (You’ll have to Google)
Download AC78x Netgear drivers version 4.3.00
Download Putty
Put everything in the same folder
Install drivers
Connect MR1100 directly to computer with USB cable
Open putty, telnet into MR1100 ip address with port 5510
Run AT!BOOTHOLD
Close Putty
Open cmd, change directory prompt to where you downloaded everything to. Type ”FDT.exe insertfilename.secc.spk” and hit enter. Do not touch anything. If the command prompt tells you after “resetting device” that the upgrade failed, ignore it and let the MR1100 do its thing. It may look like it’s frozen, but it should finish and boot by itself after about 10 minutes.

Forum Discussion

MR1100 EUS FIRMWARE PROBLEM