Solving Failed VNC Connections to OS X

My Problem

I have a new Mac Mini running OS X Lion that I need remote access to. I’ve enabled “Screen Sharing” in Sharing Preferences, created a VNC password and ensured that Screen Sharing is allowed through the firewall.

Using various VNC clients, I receive different forms of bizarre errors and refused connections. In Remmina on Fedora 14, I cannot connect to the Apple VNC server. Either a connection is made and I see a very brief flicker of a remote connection before the window is closed or the connection perpetually hangs at the “Connecting…” stage.

Using UltraVNC on Windows 7 I receive the error:

Server closed connection

– the server running as application

My Solution

Edit your bit-depth settings in your VNC client (not on the receiving Apple computer). Change the bit depth to something other than 256 colors or 32-bit. For example, I can connect to the Mac’s VNC server using 15, 16 or 24-bit color depths. As soon as I choose 256 colors or 32-bit I am unable to make a connection.

I suppose Apple wants their GUI to be enjoyed in its full glory and 256 colors is just too shabby. 32-bit? Well, that’s not minimalistic enough.


  1. […] articles Solving Failed VNC Connections to OS X ( 4 Great Screen Sharing Tools for Teachers ( Enhance OSX […]


  2. Travis

    August 21, 2012 at 10:05 am

    Ha, this worked for me. Just love the random “doesn’t work unless you do this arbitrary thing” issues.


    • Wesley David

      August 21, 2012 at 10:27 am

      I know, right?


  3. robert

    March 13, 2013 at 9:54 am

    Wow. You’re right. Thanks for this, I’d never have thought of it when figuring out why my VNC connection was failing.


  4. gnimsh

    April 3, 2013 at 1:48 pm

    Thank you! One of my users was having this exact issue.

    Any idea where the VNC server preferences are stored? I’d like to try to edit this file to remove these limitations but haven’t had any luck so far.


    • Wesley David

      April 3, 2013 at 6:20 pm

      I don’t know where the prefs are stored, sorry. I didn’t follow the issue any further than that.


  5. Omer Katzir

    April 16, 2013 at 10:03 am

    Thanks, solved my problem too!


  6. Chris Phillips

    May 22, 2014 at 12:49 pm

    How can one force UltraVNC into 15 or 16 bit color? So far as I can tell, the GUI application does not offer these options. Do I need to pass a command to the EXE or can I edit the .vnc save file to force this?


    • WesleyDavid

      May 22, 2014 at 4:42 pm

      For me there was a UI option to force it. =/


      • Chris Phillips

        May 22, 2014 at 4:50 pm

        Do you know what version of UltraVNC you were using? The versions I have are missing the option to specify the bit depth.


        • WesleyDavid

          May 22, 2014 at 4:54 pm

          I don’t remember, sadly. In two years I don’t have any of the systems I was testing this out on and have no recollection of even why I was doing this. =P


Leave a Reply

Follow TheNubbyAdmin!

follow us in feedly

Raw RSS Feed:

Contact Me!

Want to hire me as a consultant? Have a job you think I might be interested in? Drop me a line:

Contact Me!

Subscribe via Email

Your email address is handled by Google FeedBurner and never spammed!

The Nubby Archives

Circle Me on Google+!

Photos from Flickr

Me on StackExchange

The IT Crowd Strava Group

%d bloggers like this: