Message output is greyed out in WA02 (allocation table)

I want to send an EDI output from the allocation table, but in the menu of WA02 under Goto--> Messages the messages is greyed out.

All the config has been done against application WA. Message type / Condition Type / Message Schema assignment etc is all complete for single message

Also when I try trigger notification via WA11 i get (0 output was processed in total), and in debug this seems to access application WO and not WA.

Appreciate some clearance how this works..

Thanks

Farrukh