Value for parameter is not set (BODI-1111202)

Hi

I'm modifying a job made by another one to fix something and I came accross an issue : at one point I removed the DF from the Job and put it back in it and I got the error at the validation level : Value for parameter <$P_ITEM_LIST> is not set. (BODI-1111202)

To explain further, the DF calls a custom function that concatenates inside a list ($P_ITEM_LIST) the value (an item) given as parameter on a key (another parameter). If the previous key is the same as the current one, the item is added to the list. Otherwise, the list is resetted.

This parameter is declared in the Dataflow, as input. And also in the function itself (as input/output) so that the value is sent back to the DF at the end of the function.

Am I doing this properly ?

For the error I don't see where I can set a value to this parameter and by the way it's only at runtime that this list will be created.

thanks