Firepower upgrade stuck

[james.tribble]

I have a 5512X running Firepower from the ASDM.  I am trying to get firepower up to 6.2.3.12. i have reimaged the firepower twice because the upgrade gets stuck at 55% on 800_post/021_reinstall_SRU.sh.  This happened at 6.2.3.8, I reimaged was able to get to 6.2.3.8 and it happened again at 6.2.3.10.  Each time I left the upgrade running for at least a day. 

[Marvin Rhoads]

Try doing a SRU push by itself first. Often the upgrade process will hang or fail if the Snort Rules are too far out of date on the target sensor.