Responsive SSP - Error when w/o DFF 'You must provide a value for the _FLEX_Context attribute'

Client is about to enable Responsive SSP.

There are several mandatory DFFs on Requisition Headers.

When a user submits requisition without completing one of them, they hit this message 'You must provide a value for the __FLEX_Context' which is not helpful at all.

Is there any way to change error message so it points out what they need to do is to enter DFF before submitting the requisition ?

Thank you.