Problem

When we go inside a partner only one default delivery exchange could be created.
It is impossible to create a second Delivery Exchange, button "add a new delivery exchange" is not present.

This issue could occured after database export from environment B2Bi 2.1.0 (A) to another environment B2Bi 2.1.0 (B)

Resolution

1) Delete all agreements on environment B
2) Export entire system profile from environment A
3) Import it into environment B with option "Replace existing objects if encountered"

* Note that when importing with "Ignore imported objects if existing objects are encountered" the issue still existed.