I’m new to the MOX (been using Roland for 15 years). I have all of my custom presets saved to USR1. The vintage keys loads to USR3. However, when I load vintage keys, all of my USR1 presets revert to factory. Luckily I did a full backup. What did I miss?

Welcome to the forums!
What you missed is simple: The significance of the word “ALL”.

If you load the VINTAGE KEYS file using the File TYPE = ALL, it will replace all user banks with the data that is in the file. What you want to do is set the FILE TYPE = 1 BANK VOICE

This will allow you to “open” the ALL data file and select USER 3 as the one bank you want to load from that VINTAGE KEYS file.

You can then direct it to whichever internal USER bank you want it to go… for example, you could target USER 2 or USER 3.

So what you want to do is reload your USER VOICE, then when you want to add the 128 VintageKeys sounds:

Press [FILE]
Press [F3] LOAD
Set the TYPE = 1 BANK VOICE
Highlight the VINTAGE KEYS.X4A file on the right side of the screen
Press [ENTER]
The file will ‘open’ to reveal USER 1, USER 2, USER 3 and USER DRUM as banks of Voices.
Move the cursor to the right side of the screen and highlight “USER 3” (You know that the Vintage Keys Voices you want are in USER 3

Move the cursor and target “USER 2”
Press [SF1] EXEC to execute the load…

In general, an ALL data file (.X4A) or an ALL VOICE file (.X4V) can be ‘opened’ if you set the file TYPE to
1 BANK VOICE (as explained above)
VOICE - which allows you to select a single VOICE from a file and direct it to a single location.

Hope that helps.

Thanks for the quick reply. Looks like that solved my issue.