I looked at your other post. To help others understand, you are not making a square block, but a triangle shaped block. It looks like a framed triangle. The center triangle is solid white and it is framed by a long print strip with a solid diamond on each end to form the points of the triangle. These diamonds then form a 6 point star when the blocks are joined together.
I have not made a block like this so I can only offer suggestions. Did you measure each triangle to make sure they were all the same size before you sewed them into rows? Accurate seam allowances will be very important in this block. You will also have to be careful not to stretch the center diamond when you sew as it has bias edges. When sewing together the blocks, make sure you match the point where the corner diamond and the strip are joined, nesting these seams together.
You said every other row is missing a triangle at the end of the row. Do you mean the center triangle? Or the amount missing is triangle shaped?