So are you saying that you are unable to add any new plants? Then you are doing what I did earlier today, not adding the genus so it doesn't know where to place the entry within the database.
The red message you see is there at the outset, it just seems like it's now glaring at you with a new message but it has nothing to do with why your proposal doesn't go through.
Maybe Dave needs to add something to the effect that filling in the genus section is required to complete the entry.