We have identified a system crash caused by the Colored Pencils tab of the Color Picker when OmniGraffle is running on certain hardware configurations. To minimize the crashes, OmniGraffle 7.8.2 disables the Colored Pencils tab of the Color Picker when it sees that it is running on macOS High Sierra 10.13.6. This issue does not impact users on macOS Mojave 10.14.
If you are running macOS High Sierra 10.13.6 and were not effected by the crashes and you want to enable the Colored Pencils tab then you can override this change and reenable the tab using this URL: omnigraffle:///change-preference?ColorPaletteShouldIncludePencils=1
We have also found that forcing the OS to use the discrete GPU will also work around this crash. If your Mac has a discrete GPU then there will be an “Automatic graphics switching” option in System Preferences > Energy Saver. You can disable that option then use the URL above to restore the Pencil tab to your Color Picker in OmniGraffle. Or if you use a laptop connected to an external monitor then the OS will automatically switch to your discrete GPU.
