It sounds like your edge layer drawing isn’t closed. Is it an unusual shape? I know some versions of Kicad had trouble with some shapes. People are reporting that 5.1.6 is close to being released and has some important bug fixes.
Put your cursor at (202.43292 mm, 128.04394mm) (absolute values) and see what’s happening there.
As @hermit says, board outline must be closed shape, otherwise you’ll get errors like these.
I don’t feel this is a good way to share files - it asks for my email address to send the file there, and I don’t even know what’s the file size in advance.
As Rene_Poschl said, I ran the DRC,
It turns out that there were 2 lines that didn’t quite line up and I had to zoom RIGHT in to see it and it’s all okay now.