Good !

More generally, running the following Applescript should normally track down the cache location.

set strPath to GetCachePath()
display dialog strPath
set the clipboard to strPath

on GetCachePath()
	set strDefaultFolder to "~/Library/Caches/com.omnigroup.OmniFocus"
	set strAppStoreFolder to "~/Library/Caches/com.omnigroup.OmniFocus.MacAppStore"
	set strDBName to "OmniFocusDatabase2"
	
	set strCacheFolder to strDefaultFolder
	if (do shell script ("test -d " & strCacheFolder & "; echo $?")) ≠ "0" then
		set strCacheFolder to strAppStoreFolder
		if (do shell script ("test -d " & strCacheFolder & "; echo $?")) ≠ "0" then return ""
	end if
	
	return strCacheFolder & "/" & strDBName
end GetCachePath

[lpb2hao]

Originally Posted by kagey

Looks like OmniFocus trashed its own cache!
I just reopened it and no error message, and now the Folder has appeared on cache.
Thankyou:-)

Ditto. Self-healing. Bravo!

[liz4cps]

This worked for me, too. I did have to force quit it in order to quit, but it all looks good now.