Make sure you can log into the CCMUser page (http://servername/ccmuser). Not sure about 4.2, but on my 4.1(3) UCM if I can't do that I know my Active Directory integration is on the fritz. What kind of auth are you using?
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...