Editing Group "External Users" Message Settings

I'm trying to change the Message Access Permission - Message Access Permission from "Only Specified Recipients can access" to "Only Specified Recipients and Local Users can access". But whenever I try that, I receive this error banner after clicking Save: "Please remove all users from the group before changing local".

Can you explain why I would need to remove all users and how I can accomplish this with a default External Users group?

I want to change the default setting so when a client creates an account and then creates a new message, if they forget (or don't know) to CC a secretary, that the secretary can access the uploaded files without having to involve one of the addressed parties or yours truly, the system administrator.

This was one of the groups for which I hadn't configured the default message settings, but see that I should have done so, but apparently can't after the fact.

Thanks.

Cheers,
Jon

 

@Johan I had looked for a version newer than 4.1.2 on the release notes page as well as checking for updates before I posted, but I didn't see one, yet the release dates for 4.1.2 and 4.1.3 are displaying the same date?

I just successfully updated to 4.1.3 and am still receiving the same error. I'll try restarting the server over the weekend and see if that clears things up.

Thanks.

Cheers,
Jon

 

Rebooted, no change in behavior running 4.1.3.

Here's the group I'm trying to update:



This is the section which I'm trying to change from Only Specified to Specified & Local

This is the response I receive when saving.


I'm open to the next set of steps. Perhaps there's text file I can update without going through the web GUI?

Thanks.

Cheers,
Jon