Fix Snow Leopard’s Screen Sharing Black Screen Bug

[Update: This bug appears to have been fixed in the Snow Leopard 10.6.2 release on 10 November 2009. Tell us in the comments if you still have this error connecting from a Snow Leopard system to another Mac or via VNC.]

Snow Leopard shipped with a major bug in its otherwise improved Screen Sharing program. When connecting to many remote systems using Apple’s screen-sharing feature, the remote screen initially appears black. Selecting either View > Full Quality or View > Adaptive Quality – even if one of those options is already selected – typically clears the broken state. When connecting to remote VNC servers, some people see white screens instead. (For more details, see “Solve Snow Leopard’s Screen Sharing Bug,” 7 September 2009.)

TidBITS contributor Chris Pepper pointed me to a potential solution at Mac OS X Hints. The anonymously submitted advice is to change the Screen Sharing program’s mode setting to 32 bits. To make this change, follow these steps:

1. In the Finder, choose Go > Go To Folder.
2. Enter /System/Library/CoreServices and click OK.
3. Select the Screen Sharing application, and press Command-I to bring up the Get Info window.
4. Check the Open in 32-Bit Mode box, and close the window.

The next time the program is launched, it operates in 32-bit mode, which apparently solves the problem. I tested this change, and for two of the three systems I connect to remotely, both of them running Snow Leopard, the fix worked: no more black screen. A third system running Leopard continues to show a black screen and requires toggling the View menu selection.