Not able to update an attribute in Dataflow

[saloni1]

I am trying to map new data to an already existing attribute in the dataflow but I am getting the errors shown in the images.

I have added a primary key attribute in the dataflow while creating it.

[Tof_Jossic]

@saloni1 This is a duplicate of another post - let's stick to this where I already provided a response - Thank you.