If the value of processing group is blank and user takes an action then it fails.

Hello,

When I performed below steps in Task list , I am getting error.

1) login to Invoice processing task list
2) look for the task having processing group value as Blank. Open the task
3) Click on "Change Processing Group" action from the actions section.
4) on the next screen select any processing group, like "Manual Entry"
5) Click on "Ok"

Actual result:
The screen with "Error..." will be displayed

Can someone tell me why this issue occurs??

Thanks,

Rajendra