Quite a number of times I have encountered this problem with highlighting:
One highlights a verse and no words whatsoever, yet the highlight system does not highlight, but up pops the annoying rebuke window: "The selection cannot include both words and a verse reference." So then one has to go back and make sure that no space to the right of the verse number was included in the highlight. If one happens to highlight both the verse number and the empty space just to the right of the verse, this bug occurs.
Highlighting a verse with the empty space to the right of it should be treated the same as just highlighting the verse number, if possible.