I am trying to upgrade ROMMON on 4331 from 15.4(r3)s5.

[sk002]

I am tying to upgrade the ROMMON from 15.4(r3)s5 to isr4200_4300_rommon_1612_2r_SPA.pkg

the output I get when I type in: upgrade rom-monitor filename bootflash:isr4200_4300_rommon_1612_2r_SPA.pkg all

Chassis model ISR4331/K9 has a single rom-monitor.

Upgrade rom-monitor

Target copying rom-monitor image file
selected : 0
Booted : 0
Reset Reason: 0

Info: Upgrading only BIOS from the rommon package
4259840+0 records in
4259840+0 records out
4259840 bytes (4.3 MB) copied, 10.7823 s, 395 kB/s
262144+0 records in
262144+0 records out
262144 bytes (262 kB) copied, 0.777734 s, 337 kB/s
655360+0 records in
655360+0 records out
655360 bytes (655 kB) copied, 1.78389 s, 367 kB/s
File is a FIPS ROMMON image

what could be the problem? 

I also have tried an older version of ROMMON and same thing happens...

[pseduopacketor]

I encountered a similar issue that I found was a bug, my ISR 4300 was on version 16.3.5 and rommon 16.2.2(r) and I had to rollback the version to 03.16.04b.S and then that allowed me to upgrade the rommon to 16.12.2(r) without issues. After upgrading the rommon, I reloaded the router and was able to upgrade to the golden IOS version. 

Bug: https://quickview.cloudapps.cisco.com/quickview/bug/CSCvg52180

[FatihGurbuz]

problem solver thanks