Table of Contents
Installing the IMVU Toolkit for Blender on MacBook or other MacOS computers will generally result in the “FILE NOT FOUND! : IMVUMegaScene.blend” error. The fix for this is two-fold; first download the Toolkit from IMVU and install it as is normally done for any Addon, this creates the necessary directory structure for the fix; second, copy the ZIP archives contents into the addons folder generated from step one. Once this is done the Toolkit can be used as normal.
Design note: Toolkit does not specifically need to be installed but doing so saves having to create the directory structure necessary to get the Toolkit working.
Addon File Path
Installing the Addon provides a means to verify the live path  that needs to be followed to fix the problem with the Toolkit not installing correctly. This should be (where [username] is the Account used to log into the system, and [version] is the version number attributed to the installation, i.e. Blender 3.6 LTS is referenced simple as 3.6);
Generally speaking the IMVU Toolkit addon needs to be installed as a User file but looking at that location in the Finder only shows Documents, Downloads, Music, Pictures and so on, Library, because it’s a system location, is hidden from view. To see it, use Control + Click ( + LMB) to access the context menu and select Show View Options. In the panel that appears click the checkbox next to Show Library Folder  to make the Library folder visible in Finder.
If the directory has been created as a result of installing the addon, in a Finder instance click the ‘user’ , e.g. “katsbits” in Favourites or “KatsBits’s MacBook” under Locations, and continue to follow the path;
Open a second Finder window, locate the downloaded ZIP archive – typically its in Downloads or on the Desktop – and copy IMVU-Studio-Toolkit-Blender[n]  from where it is, in to addons.
Manual Folder Creation
If the IMVU Toolkit for Blender was not installed the addons folder, and directory path to it, needs to be manually created. Starting within the system folder Application Support;
If the Blender folder does not exist create it – Control + Click » New Folder. Inside this new folder create a number-labelled folder that corresponds to the installed version of Blender, e.g. 3.6. Inside this numbered folder create scripts. And finally inside scripts create addons.
Times are approximate;