I have had Arcus running on my dl4100 for almost 2 years. I had 5 licences and today I tried to add another camera. Every time I inserted password etc. it said invalid even when it was correct, so I removed a camera that was running and re added it. Same problem password not correct. Anyway I thought maybe there was a glitch in the program so I uninstalled it and tried to reinstall. To my dismay the arches program has been removed from the list of programs to install. Has anyone else had this problem. Has WD removed it from downloads?