Take a look at this message explained by BB-Jason>
(168634.11)He mentioned that it was previously state but unfortunately I fail to acknowledge it earlier because I don't know where it is stated but anyway, you'll just have a lesser total scouting point next season, we have many more season, try investing again in season 16.
For now, the scouting points getting negative here, and it is said that how much you spend for scouting this week will be brought to season 15, and the reason we are getting a negative figure is that we have already use it before next season, therefore, if we spend 40k/week for this week, we'll have 4 points, and if we use it we'll get -4, then in the next season, the system will add back 4 points which we have spend for scouting this week, thus the next time you open your draft and scouting page you'll see a 0 scouting points available.