I just got off the phone with Cisco Tech troubleshooting ISR4321 Boot up problem:
the command: boot system flash bootflash fixes the problem.
router# conf t
router(config)# no boot system
router(config)# boot system flash bootflash:isr4300-univer...
May-June 2019: I Received a shipment of new ISR4321 routers. Some helpful notes listed below: ***2 different Processes worked for me****1. If the system is caught in a boot loop...this can happen if you use: boot system flash: alk9.03.xxxxxxxxxxxxxx...
