This one is driving me crazy. I downloaded the latest Nagios preconfigured VM. After following the instructions and successfully logging in with the root account I try to launch NagiosXI.
Thanks for the response, here is a screenshot of what I get when I try that command as well. I should have mentioned that I tried that, but I gave it another go just in case. I'm a Windows Admin, who has used Linux for Snort and Nessus and that's the extent of it. It appears to be permission related.