How to add a new line if no blank lines available

This is related to bug #308048

A bug occurs within the GUI when blank trailing lines are deleted within a table in OpenScore. The user is then unable to add further information to that GUI page until the application is restarted.

The way I see it, there are two solutions to this:

1. Add an 'Add New' button to every page that resets the table, adding the +1 blank line for adding data in; and/or
2. Add a self check mechanism into the application where if I click the inactive lines within the table (that is, the non-data lines including +1 blank lines), it checks to see if a +1 blank line already exists in the GUI.
  IF YES, do nothing.
  IF NO, add a new +1 blank line

How should we overcome this problem?