Hi Deane,
Here are the sizes of the USER flash memory in recent arrangers (taken from the Specifications table in their respective Owner's manuals)...
Tyros3 3.2 MB
Tyros4 6 MB
Tyros5 approx. 6.7 MB
PSR-S950 approx. 6.7 MB
PSR-S970 approx. 13 MB max.
PSR-S975 approx. 13 MB max.
As you can see, the USER drive on your S975 is bigger than any other Yamaha that you have owned!
Some of the user drive is required for the 'Expansion' folder where styles, registrations, multi pads and small voice data files from installed Expansion packs are saved when you install Expansion packs from YEM. The much larger wave files from these packs are stored in the 768 MB of Expansion flash memory. Have you got a lot of Expansion packs installed?
Within YEM, as you select packs/files to include in a '.ppi' or .cpi' Install file, it will show you how much space the currently selected items will require in the USER drive, but it doesn't know what is already currently saved in the non Expansion folders on the USER drive, so it can't give you a total for everything.
I don't know if you can see the available space in the USER drive from the keyboard, but if you connect it to a computer and use Yamaha's 'MusicSoft Downloader' program, you should be able to see everything that is stored in the USER memory at that time, which should tell you why you are having problems.
Also bear in mind the maximum number of items in a folder is 500. Could this be what the message was about?
There are also 'Notes' in the Owner's Manual about other restrictions for the USER drive. For example, the following from page 29...
"In the USER tab, no more than three
folder levels can be created. The maximum
total number of files/folders
which can be saved differs depending
on the file size and the length of the
file/folder names."
Could the error message relate to this?
Regards
Ian