Convert a Pure Activity to a Block

Change 'Pure' to 'Block'

  Q      How do I convert an existing “pure class” activity (one group/subject) into a “block” (2+ groups or subjects) ?

  A     One way is to delete and enter again ... but a better way is this:  On the Curriculum Diagram (or in the Batch), double-click on the lesson you wish to convert, then click on the “Staffing” Tab, and click “Convert to Block”:

You can then add the extra/second subject(s):