Error after Task duplication

Hi there,

I am totally new to omniplan
use a german version, so I don’t know the English names and error codes but will translate them as good as possible.

Here is my problem:

As you can see I designed a project and added one group task that has several tasks and grouped tasks below.
Everything is perfect no errors whatsoever but if I copy this main task because I need it a second time, for the second task errors that are related to subtasks are shown and is told that these are not solvable.

Error is: “This operation could not be inserted during resource leveling”

In the description to this error it says: “The resources could not be fully matched for this operation.”

Could you help me that would be much appreciated.


At least i figured out that it has something to do with the resources. If I add a resource the error appears, even if I do the green button “plan project new” with option control resources automatically.