After considerable frustration and trial and error, I've debugged this issue on my own and here are my findings for other frustrated users. I hope someone finds this useful.
I am speaking only to those who installed Modo Drum CS and then perhaps updated or reinstalled or changed a path and then became stuck with the content pak missing error or worse yet the content pak missing and no way to access changing any paths from within the app. Also I am on mac so can't speak to pc resolution.
First, if you are able to change the path, make sure the following is true:
The following files and directories are in the following locations:
Location = /Library/Application Support/IK Multimedia/MODO DRUM/
Files and Folders =
Grooves ( folder aka directory)
MIDIMapPresets ( folder aka directory)
ModoDrum.pak
ModoDrumConfig.pak
ModoDrumFactoryContent.pak
Location = /Users/Shared/IK Multimedia/MODO DRUM
Files and Folders =
ModoDrumFactoryContent.pak
If any of the above does not exist or is not existent, create any missing folders exactly and copy ( don't move ) files where they should be until you have this exact configuration.
Then, restart ModoDrum and make sure that the sound library path is set to the /Users/Shared/IK Multimedia/MODO DRUM location.
This should get you up and running.
If you aren't able to access the changing of the path option from within the app:
You will need to go to the User Library ( if you don't know how to access this directory, you should probably just submit a ticket with IK and have them walk you through troubleshooting and not mess around in this hidden directory - it's hidden for a reason
) ...
Location = ~/Library/Preferences/
and find this file ->
com.ikmultimedia.MODODRUM.plist
From within that file ( I used the Visual Studio Code app to make this edit ) You will need to manually edit the "LibraryPath" Key and the "NSNavLastRootDirectory" to state the following path locations:
/Users/Shared/IK Multimedia/MODO DRUM
You may be tempted to simply delete this preference file thinking it will be rebuilt to its default state. It won't, it persists, so go ahead and make the edit.
Optional, but, advised as good practice> Restart your computer at this point.
Open MODO DRUM and you should find that you again have access to change the paths from within the app, but, you shouldn't need to since you already did so manually in the previous step and if your file structure is as initially stated this is the correct path to use anyway.
I believe this is a pretty significant and frustrating bug in the updated Modo Drum 1.5 app. I didn't dig too deep, but, it would appear that the older version installed and looked for the ModoDrumFactoryContent.pak file in the Library/Application Support/IK Multimedia path.
However, the updated version defaults to the /Users/Shared/IK Multimedia path and should the path from within the app be set to the original default path, even if the ModoDrumFactoryContent.pak is there, it will say that it is not there etc. and in certain combinations the app will lock out any ability to change the path.
Not having the ModoDrumFactoryContent.pak in both locations but in the correct combination of path and file/folder data will work in some instances but I wouldn't trust them and would just keep the ModoDrumFactoryContent.pak in both locations and the file path set to the new /Users/Shared/IK Multimedia path in order to have a working 1.5 version and wait until IK Multimedia sorts this bug out in the code logic.