Hi m.mittelmann,
I can’t reproduce the problem here. Do you have a small scene file that you can share? Just a single object, and how you would like to use the Vertex Maps? Weight Maps or Vertex Maps?
Since I have no further information, I can only ask: Would it work in your set up to combine all Vertex maps into a new one? Please have a look at the example below:
https://www.amazon.com/clouddrive/share/PMsfooEVv3S77XOdet18xUQ3clbgGM2rZFUeaCuWPcS
Is it possible to copy the objects from the Object Manager, and paste these into a new scene? Same problem?
I assume anything on your system is up to date.
Perhaps that is a case for the support.
https://www.maxon.net/en/support-center
Let me know if you need an upload link. (I open only DropBox, Amazon, Google, Apple or Adobe cloud service links). I’m happy to look into your file. IF it holds the term “private” in the name, I will keep it so.
All the best