Hope this helps identifying the problem.
I also tried clearing the tmp folder (in windows10 it's C:\Program Data\Arturia\PianoV2\tmp), to no avail.
The crash occurs in standalone mode when changing piano tuning from American Grand to any upright model. Changing from American Grand to the other grands works fine.
The crash does NOT occur when changing presets from American init to any other preset. Changing to any other tuning -upright or grand- from that preset, works fine.
Once you have done this, changing the tuning to upright from American Grand works like a charm, even when going back to American init preset and changing the tuning from there.
I closed and restarted the program, and the crash no longer occurs when changing tuning from American Grand to any other tuning, while staying within the American init preset.
My guess is changing the American init preset to any other preset before changing the American Grand tuning to any upright solves the problem.
So it is a bug IMHO, but one that can be easily resolved.
EDIT: In my DAW (Bitwig2.2.2, 64bit) the above solution did not work initially. Changing tuning from American Grand to any upright crashes the plugin. Changing to any other grand works fine. Changing presets from American init to any upright preset also crashes the plugin, changing presets to any grand preset works fine.
But, changing to upright presets or tuning, starting from any grand preset other than American init, solves the problem. Returning to American init after doing this lets you load upright tunings and presets.
The problem re-occurs when closing Bitwig and restarting Piano V2 in a new project and in a saved project.
best regards
Peter