That's because you can't overwrite a stock Montage performance. You first have to same it as a custom performance (rename it) and then the next time to tweak it you will be able to overwrite it if desired OR same it as another new performance.

Hey Bad Mister-
When make a tweak to a stock performance (say CFX+FM EP) and try to save it by going to Store, the option for Overwrite Current perf doesn't display as on page 32 of the owner's manual.
Any ideas?

Hey Mark,
In the Montage you have 1920 Factory Performances that are Preset. These can never be lost, they are permanently stored in the Montage ROM. You can, of course, edit them but your edits are stored in the USER memory area. This is similar to our previous synthesizers where there are PRESET and USER Banks. This still exists. The difference in Montage is the USER memory is completely empty when you first get your Montage. There are some 640 locations for you to store your own Performance creations (5 Banks of 128)... be they variations on the Presets or ones you build from scratch.

In the MOXF/Motif XF/XS the USER banks were always occupied by "placeholder" programs, that you overwrote. The Montage is very streamline, you have 0 Performances out of 640 when you first get your Montage. You can see how many PERFORMANCES you have by going to the following screen:

Press [UTILITY]
Select "Contents" > "Data Utility" > select the "PERFORMANCE" folder...
You will see a box for each Performance you have created and the counter in the upper right corner will indicate how many out of 640 you have...
You can view then alphabetically (Name) or by chronologically (Date).
If you press "Job" in the extremely upper right corner you can SELECT individual or SELECT "All" and Delete them.

Managing your internal Memory is done in this Folder.

When you create a USER file .X3U, you will save only the data you have created. This streamlines the file and is efficient use of memory, instead of storing "placeholder programs".

If you make a change to the Factory Preset "CFX + FM EP" you must store that to your USER memory.

Try this to better understand the Memory locations:
Call up "CFX + FM EP"
On the HOME screen tap the Name _ a pop-in from the left side of the screen appears.
Touch "Property"
Here you will see that this PERFORMANCE is in the Piano/Acoustic Category, is in the PRESET bank and is located at MSB 063/LSB 064 Program 001

When you create and store your first USER PERFORMANCE, be it from scratch or an edit of a PRESET it will be directed to MSB 063/LSB 080 Program 001. This is the first of the USER banks.

It occupies the lowest numbered empty location in your Performance Folder. Once you have data in your USER PERFORMANCE folder, (and we highly recommend you rename any program you STORE even if it is just to add your own initials), if you decide to further edit this PERFORMANCE, you will then be asked if you want to OVERWRITE your USER Performance or create a NEW USER Performance. Make sense?

Only USER data can be overwritten. You will never lose "CFX + FM EP" it is literally, pre-set.

Got it.. Thanks for both responses.
Bad Mister- Yep, understand that I need to re-name the performance something intuitive that will make sense for me otherwise I might have multiple copies of the same performance with different settings all named the same thing.

You can also change the Category and Subcategory of your Performance, which could help you find it again in the future.

The Performance gets its category settings from Part 1, so you have to set them there.

The way to do this was quite unintuitive to me -- I think it would be better to have an explicit place in the Performance itself (separate from the settings for Parts) for the category settings. Perhaps something to think about for future firmware upgrades…