Unable to create a new patch

I am trying to create a new patch of my plugin, but keep getting the error "Ensure the version number is higher than the version number of the previous patch (0.1.2)" even though I have entered 0.1.3. I have also tried 1.0.0 and other numbers higher but nothing will be accepted. I have tried filling out all the other text boxes on the page, but nothing seems to allow me to create a new patch.