I do see what you are saying about the upper right. I would re check the size of my pieces. The colors are great and the pattern is great. I am sure you will be able to figure out the corner. Just step back for a few minutes and look at it again. I'm sure it'll come together. I have had to do that a lot. It is not easy to find your own mistakes. I have always said there should be at least two sets of eyes looking. That comes from working in accounting most of my life. When I couldn't find error, would ask someone else to look at those numbers.