Expression Map bug

Hello guys,

I have a problem with expression maps. When I play or listen to Midi Vsti with Expression Maps, it randomly stops the sound and resets the Expression Maps while I’m playing or listening. If I do not use the expression map it works. I use blank maps and it did not reset the map, but the sound stop randomly. It appear often and since I upgrade from Cubase 9 to Nuendo 10.3.

I try to check or uncheck some options, but it did not work.

I use keyswitch maps with direction and Kontakt 5 VstI.

Am I the only one with this problem? I didn’t find anything on Google.

There’s a thread on the Cubase side about an issue which is probably what you’re experiencing too. Cubase 10.5 is basically the same version as Nuendo 10.3 for this purpose:

Unfortunately no fix for either Nuendo or Cubase, so I’m sticking with Nuendo 10.2.20 for the time being. I suggest you try that version as well.

Has Steinberg acknowledged this bug?

It appears quite hard to reproduce, probably why it’s taking so long. But it seems a couple people have figured out 100% repros so hopefully that helps Steinberg fix it.

This bug is killing me. Any help in sight?

this could be related. CC messages at the start of a MIDI part are not always triggered or reliably chased. (E.g. a CC at may not be triggered if your MIDI part also starts at

Thank you all.
I´ve downgrade to Nuendo 10.2 and it works well for me.

I wonder if the size of an expression map makes a difference. My maps usually have more than 10 articulations per instrument.
I downgraded to 10.2, which makes the problem less severe, but it’s still there.

Would really appreciate an update from Steinberg on whether we can expect a fix for this in the next maintenance update, or if there’s a known workaround that we could use if we want to use some of the new 10.3 features.


Once my session gets to a more complex orchestration, it becomes unusable in 10.3 and I have to continue in 10.2.