Multiple Solutions?

[littleredbender]

I've had this happen a couple of times but just now managed to get the screenshots. I solved in the sense that all criteria were met and all ship lengths were used. However, when I hit "check," there are errors displayed. Am I misunderstanding something? Or do some of these just have more than one solution?

[Anachronismatic]

The one on the left has a single-celled organism touching the one with length of four. They can't touch on the corners.

[littleredbender]

The one on the left has a single-celled organism touching the one with length of four. They can't touch on the corners.

Thank you so much...I don't know how my brain wasn't seeing that!