Depth chart issue/bug

I am doing a season in GM mode only and on a couple of occasions the game is giving a red warning "Missing a player on depth chart" at the top of the screen on the current team I am managing. When I go to the depth chart there are green check marks on the bottom of the matrix for each box indicating that it should be fine. When I try to play/sim to the next day it continues to give the warning and will not advance to the next day. The first time it happened I restarted my dynasty thinking it may be a one time bug but has happened again. Do you have any suggestions as to why it may be doing this? Thanks for any response.