did you already completed 5 weekly missions?

i seems that if you complete 5 missions, you cant complete any more.
i had the same situation
http://image.prntscr.com/image/4fd406194dd04488957704a5441e5a52.png

so next time only complete 3 of the lower ones and the 2 S rank missions, i thought i could do the 2 S rank and 5 normals, but no, 2 S ranks and 3 normals