Out of curiosity I installed CrashPlan on my Ubuntu 14.10 running Plex/PlexConnect.
The purpose was to see if CrashPlan could solve the chaos we have having backups och the photos.
In the end, I would have a USB-drive at a friend and make backup of my data to his place, but never mind that now.
I installed CrashPlan (had to make changes in the install.sh due to a higher java version), med all settings and voilá: I had a backup of the iPhoto library on the Ubuntu :-)
Now, my wife told me that the ATV was hanging on the "Connecting to Trailers" :-(
I tried to explain to my 2 year old that I had not done anything to spoil his Curious George and Cars sessions, but sometimes facts don't apply...
Since the rest of the clients to Plex were all up and running I started to check the log files from PlexConnect.
There I found that PlexConnect couldn't connect to Port 80 and then it terminated.
Saving the next day, I uninstalled CrashPlan and PlexConnect was happy again.
Any suggestions on how to have both PlexConnect and CrashPlan on the same machine?
Just be aware that you cannot just change the port, you will need to setup a reverse proxy on your Apache install (there are a few threads if you search for Apache).
The other option is to change the other web page or program that is hogging port 80 instead.