I have developed a custom report which takes shipment number as parameter. when the report is run manually it works as expected. I need to load this report via an action in shipment screen. to do that I added an action as bellow. when click on that action button it opens a new tab and give the null reference error. I tried changing the configurations f the parameter in the report, but nothings work yet.
I have attached the report also with this.
Following is the Action
