I, too, downloaded the latest update this evening via the WebUI, but Sonarr never restarted. This appears to be the relevant log info:
`15-11-17 21:24:56.8|Info|UpdateApp|Starting Sonarr Update Client
15-11-17 21:24:57.1|Info|UpdateApp|Updating Sonarr to version 2.0.0.3572
15-11-17 21:24:57.4|Debug|UpdateApp|NzbDrone process ID: 10580
15-11-17 21:24:57.4|Debug|UpdateApp|Arguments:
15-11-17 21:24:57.4|Debug|UpdateApp| 10580
15-11-17 21:24:57.4|Debug|UpdateApp| /var/folders/jy/qzwtx2115xdf1s_vljvj56pw0000gt/T/nzbdrone_update
15-11-17 21:24:57.4|Debug|UpdateApp| /opt/homebrew-cask/Caskroom/sonarr/latest/Sonarr.app/Contents/MacOS/NzbDrone.exe
15-11-17 21:24:57.4|Debug|UpdateApp|Using executing application: /opt/homebrew-cask/Caskroom/sonarr/latest/Sonarr.app/Contents/MacOS/NzbDrone.exe
15-11-17 21:24:57.4|Debug|UpdateApp|Executable location: /opt/homebrew-cask/Caskroom/sonarr/latest/Sonarr.app/Contents/MacOS/NzbDrone.exe
15-11-17 21:24:57.4|Info|UpdateApp|Starting update process. Target Path:/opt/homebrew-cask/Caskroom/sonarr/latest/Sonarr.app/Contents/MacOS
15-11-17 21:24:57.4|Info|InstallUpdateService|Verifying requirements before update…
15-11-17 21:24:57.4|Debug|ProcessProvider|Finding process with Id:10580
15-11-17 21:24:57.4|Warn|ProcessProvider|Unable to find process with ID 10580
15-11-17 21:24:57.4|Fatal|UpdateApp|An error has occurred while applying update package.
System.ArgumentException: Process with ID doesn’t exist 10580
at NzbDrone.Update.UpdateEngine.InstallUpdateService.Verify (System.String targetFolder, Int32 processId) [0x000c3] in m:\BuildAgent\work\6c3239faf2b92630\src\NzbDrone.Update\UpdateEngine\InstallUpdateService.cs:75
at NzbDrone.Update.UpdateEngine.InstallUpdateService.Start (System.String installationFolder, Int32 processId) [0x00000] in m:\BuildAgent\work\6c3239faf2b92630\src\NzbDrone.Update\UpdateEngine\InstallUpdateService.cs:79
at NzbDrone.Update.UpdateApp.Start (System.String[] args) [0x00020] in m:\BuildAgent\work\6c3239faf2b92630\src\NzbDrone.Update\UpdateApp.cs:59
at NzbDrone.Update.UpdateApp.Main (System.String[] args) [0x00042] in m:\BuildAgent\work\6c3239faf2b92630\src\NzbDrone.Update\UpdateApp.cs:43 `