Hi, I'm having this problem in El Capitan 10.11.4 I was previously able to run the itch app, so not sure what has changed. Have re-installed but same result.

Here's the relevant part from the console log:

02/05/2016 11:33:14.305 lsd[316]: LaunchServices: Could not store lsd-identifiers file at /private/var/db/lsd/com.apple.lsdschemes.plist
02/05/2016 11:33:14.309 lsd[316]: LaunchServices: Could not store lsd-identifiers file at /private/var/db/lsd/com.apple.lsdschemes.plist
02/05/2016 11:33:14.323 com.apple.xpc.launchd[1]: (com.apple.xpc.launchd.oneshot.0x10000015.Electron[12666]) Could not find and/or execute program specified by service: 2: No such file or directory: /Applications/itch.app/Contents/MacOS/Electron
02/05/2016 11:33:14.323 Dock[319]: spawn_via_launchd() failed, errno=111 label=[0x0-0x219219].io.itch.mac path=/Applications/itch.app/Contents/MacOS/Electron flags=1 : LaunchApplicationClient.cp #963 LaunchApplicationWithSpawnViaLaunchD() q=com.apple.root.default-qos
02/05/2016 11:33:14.323 Dock[319]: spawn_via_launchd() failed, errno=111 label=[0x0-0x219219].io.itch.mac path=/Applications/itch.app/Contents/MacOS/Electron flags=1
02/05/2016 11:33:14.324 Dock[319]: LSOpenFromURLSpec(file:///Applications/itch.app/) failed with -10810
02/05/2016 11:33:14.331 lsd[316]: LaunchServices: Could not store lsd-identifiers file at /private/var/db/lsd/com.apple.lsdschemes.plist

Hey there, the reason behind that is an upgrade to the latest electron / electron-installer, which now generates .app bundles with an executable named @appName rather than have it simply be named 'Electron'.

However, OSX is for some reason caching the name of the executable in the app bundle and is trying to open the old one (which doesn't exist anymore once the app has upgraded). Rebooting definitely fixes it, maybe there's a less radical solution (is restarting LaunchServices possible? at least make sure there's no running instances of itch.app anymore)