Loyalty Management - Error when save Reward Rule

Hi Experts,

I have created a new dynamic attribute with ID: Z_DEMO_COUNTER (see attachment). This dynamic attribute is assigned to my loyalty program and this attribute is updated correctly.

Now I want to create a new reward rule that triggers the change of the tier level of the membership when a specific points amount is reached (see also attachment). When I try to save the reward I receive the error message that ID ... is initial, unknown or it does not have the correct object type.

What does that supose to mean?

Any help is greatly appreciated.

BR/

Oliver