I am also experiencing the same issues inside the Console...seeing the message:
7/3/12 6:33:16.685 PM ScreensharingAgent: mach_make_memory_entry_64 failed, (os/kern) invalid address
Over and over and over...last time it lasted for 21 minutes, one entry each two seconds.
Running Macbook Pro/i7 2.6/8GB - Lion 10.7.4, with all applicable updates.
I tried using ScreensConnect this afternoon to remote in and got nothing but timeout errors from my phone. Tried it on WiFi and 3g just now, no errors-connected just fine.
Also the same as the OP--screen was asleep, system is set to not go to sleep.
I have removed ARD Client completly and reinstalled it. It solved my problem.
I have removed it like Mabel O\'Farrell suggests in this thread: https://discussions.apple.com/thread/2119888?start=0&tstart=0Stop the 'Remote Management' in the 'Sharing' System Prefpane. Then in Terminal.app do:
sudo rm -rf /System/Library/CoreServices/Menu\ Extras/RemoteDesktop.menu
sudo rm -rf /System/Library/CoreServices/RemoteManagement/
sudo rm /System/Library/LaunchAgents/com.apple.RemoteDesktop.plist
sudo rm /System/Library/Launchdaemons/com.apple.RemoteManagement.PrivilegeProxy.plist
sudo rm /System/Library/Launchdaemons/com.apple.RFBRegisterMDNS_RemoteManagement.plist
sudo rm /Library/Preferences/com.apple.RemoteDesktop.plist
sudo rm /Library/Preferences/com.apple.RemoteManagement.plist
sudo rm -rf /Library/Receipts/RemoteDesktopClient.pkg
Then I have downloaded and installed Apple Remote Desktop Client from here: http://support.apple.com/kb/DL1532?viewlocale=en_US&locale=en_US
And it works! Finally!
Hello. On the system that I want to connect to, Lion 10.7.4, I have disabled anything in Sharing Preferences and removed the ARD Client 3.5.3 using Terminal, as I described above. Then I have installed on that system ARD Client 3.5.3 (the same version) that I have downloaded using the link above and enabled Screen Sharing. After that I could connect to the system whether its display is sleeping or not.
I think there is something wrong with 10.7.4 update, wich also includes the ARD Client update, so removing the ARD Client and reinstalling it separately saves the day.
I didn't install anything concerning remote connectivity/administration except the ARD Client (which I just reinstall) on the system to be controlled.
And it is not necessary to enable the screensharing or remote connect service on the system you want to conect from.
I'm still a bit confused. So I need ARD on the system I want to control from. That's pretty clear to me.
The system I want to connect too, needs some component to support remote administration / screensharing. My understanding is, that this is part of the OS anyway. So no need to install anything.
So with ARD I see my system I want to control, and it shows the correct status, actual program in use, logged in user etc. All this is correct and changes when I use a KVM to change things. So, there must be a connection between the two systems.
In the console logs I see that the screensharingd reports a successful authentification for the ARD user. About 3:20 minutes later I see a message that screensharingd can't get the width and height of the display. Well, there is no display connected to the Xserve, but an IP KVM (which I don't like to use, only for worst cases, because it's scrap) is connected which plays like a 1280 x 768. I tried switching to 1024x768 but no success.
So, I really don't have a clue where to search for. Disabling the firewall doesn't help (I thought maybe a rule blocked it). I have ARD 3.6 on all systems.
For the system you want to control: ARD Client is a part of the system. After 10.7.4 update it doesn't work properly in some cases, so if it doesn't it's better to reinstall it (ARD Client, not the system) as I described above.
Note that ARD Client is not an Apple Remote Desktop administration utility that costs money.
ARD Client also serves for Screen Sharing feature, which you can enable from System Preferences.
For the system you want to control from:
You don't actually need a paid Apple Remote Desktop or any third party VNC app to control other mac's screen.
If the Screen Sharing feature is enabled on the remote mac, and both macs are in the same network (or VPN, or with the same Apple ID and Back to my Mac feature enabled), you can select the remote mac in Finder's sidebar and press Screen Sharing button. You can also use any VNC client to connect to the remote mac's screen from the iOS device.