We are having issues with UC520, where it gets hang when I run any debug commands.Once I reboot it everything works fine but stops working after some hours. I am not able to figure out what could be the issue.
Can you please make sure that before you do the upgrade that you make a text file backup of both your CME & CUE configuration.
Since your IOS is quite old, and you are making a massive jump to a significantly more newer IOS, you may experience some problems. And also please keep in mind that the upgrade will have truncated some old commands and you may find some things missing in the command line.
Otherwise, please do the upgrade with CCA, it should work and it should resolve some of the problems, but if CCA creates problems then revert back to manual upgrade.
David Trad. davidtradconsultinggmail.com
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