Cubase Pro 11 crashed after flatten chain

Hi There,
This week I upgraded from Artist 11 to Pro 11. I usually use the arranger track. Now, when I am happy with the arrangement I like to use the Flatten Chain option, but immediately a crash report pops up mentioning a serious problem.
Is this a known problem and how to solve it? I tried different projects, the problem occurs each time.Cubase 64bit 2021.4.14 (858.4 KB)

Hi and welcome on the forum,

No, this is not a known issue. Could you attach the .crash/.dmp file, please?

Mac: macOS Console utility > User Reports folder or Crash Reports in macOS 10.15 (or ~user/Library/Logs/Diagnostic Reports).
Win: Documents/Steinberg/Crash Dumps

Hi There Martin,
I just uploaded the dmp file.
In the mean while I notised that when I restart computer and then try flatten the chain within the same project cubase immediately crashed and gives 2 pop ups with the same info.
Then, when starting a new file, create chord track and groove agent track and make a little arrangement, the flattend chain function appears to be worken. Then go back towards the first project this one olso seams to work okay when flatten chain is activated.
But…when performing an audio mixdown during a cubase session (one or several projects), the crashes appears to be back?
I already made a support ticked at Steinberg yesterday.
Maybe with this little extra description and workaround you have a solution?


Reported to Steinberg. Thank you.

What graphic card do you use, please? Do you use any custom colors in the project or do you use factory colors?

Could you try in the Cubase Safe Start Mode [Disable preferences], please?

Hi, NVIDIA Quadro k4000
I Use different colors for the track, but only the predefined ones.
And added customur made instrument pictogram.


Thank you for the clarification. I added this information to the report for Steinberg.