gphantom: Glad your situation got resolved, unless you breathe midi and opcodes it's just waiting for others with that knowledge to take action on your behalf. tldr stay off the black keys
Ok, I got an email from Arturia support (April 28, fairly quick). I followed the instructions and now I can save sequences again without nuking the device memory. In case anyone else has this problem, the instructions came in two categories, Keystep and MCC:
Keystep instructions:
1- Please reinstall the latest Firmware update using the MIDI Control Center
2- Please perform a Factory Reset to your KeyStep,To factory reset your KeyStep, follow these simple steps:
The Octave buttons are also used to reset all features of your KeyStep back to the factory specifications. To do this:
- Unplug KeyStep from its power source
- Press the Oct- and Oct+ buttons and keep them down
- Plug KeyStep back into the power source, KeyStep will go through a longer version of its power-up LED sequence, which will end with the Hold/Shift/Oct-/ Oct+ buttons flashing in a circular pattern twice.
MCC Instructions:
I- Please uninstall the MIDI Control Center using the following application:
https://freemacsoft.net/appcleaner/(just drag and drop the MCC icon on the application and uninstall.
II- Download the following version of the MIDI Control Center:
http://downloads.arturia.net/extra/mcc/MIDI_Control_Center_1_11_0_1513_ALLPRODUCTS.pkgII- Install the MIDI Control Center using that installer.
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My response to the response was a bit late as I wanted to make sure it was resolved. Not sure which step exactly fixed it, but it works. Thank you thank you!