SUCCESS!!!!
After a few back and forth emails with support, we stumbled on a solution that worked.
NOTE: This was tested on Mac OS 10.10.5 (Yosemite) but should work for earlier and later versions of Mac OS X
First go to your HOME folder (often generalized with the "~" symbol). This folder will be in the Users folder of your Macintosh HD and be labelled with your login account name.
Open the Library folder within your HOME folder.
If you can't find this folder, then go under the Go menu in the Finder and select Go To Folder... (Shift, Command G) and type: ~/Library/
In the Library folder, locate the Application Support folder
In the Application Support folder, locate the GOG.com folder.
Select or highlight it and "Get Info" (Command-I)
At the bottom of the info window there is usually 3 permissions entries, Most will have Read Only. You need to click a tiny lock icon in the lower right corner and then type in your computer account password (Admin password, essentially)
Now change the permissions so they all say read&write.
Select the small drop down located just below the permissions entries and choose "Apply to enclosed items" and then close the Get Info window.
(This should prevent you from having to constantly typing your PW each time you create a new folder for this solution, as well as reduce the likelihood the folder will generate as read only for other games)
Now we will generate the folders needed SPECIFICALLY for Leisure Suit Larry 7:
Open the GOG.com folder
It is likely the error on saving is because the folder hierarchy is missing, and the permissions failed to allow it to be generated, so here is the series of folders to create for LSL7:
Within the GOG.com folder, if it does not exist already, create a new folder and label it:
Larry 7 (include the space between the name and the number)
Open this folder and create a new folder and label it:
Sierra
Open this folder and create a new folder and label it:
Leisure Suit Larry 7 (with spaces between each word and number)
Double-check this last folder with Get Info and make sure the permissions are set to read&write for all categories like you did with the GOG.com folder, in case it generated it wrong
So the hierarchy of folders should be:
~/Library/Application Support/GOG.com/Larry 7/Sierra/Leisure Suit Larry 7
Once this is done, close all windows and relaunch the game. It should allow you to save now.
Now if you will excuse me, I have a Cruise Ship to catch, and lovely ladies to embarrass myself with :)
Post edited April 26, 2016 by Strongblade