Please inform me how to restore my Shared Plug-Ins, as they do not show up in Music Creator anymore.

First use Windows Explorer to verify the path to your shared plog-ins directory.  Then go to Utilities > Cakewalk Plug-In Manager to run the plug-in app.  Finally, click on the "Options" button to view the plug-in paths.  If the path you followed in Windows Explorer is not listed then click the "ADD" button to add the path and rescan for plug-ins.
 
My directions are for Music Creator 6.  The directions may be a little different if you are using a different version of Music Creator.

The Sonitus Equalizer has gone missing within the past month, and I do not see it in the Plug In Manager.  But it does come up when searching for it in my Windows File Explorer.
 
So...  OH!!!  It was not enabled for some reason.  I enabled it.
 
Thank you!

Glad you read you got the problem resolved.