These problems seem to be corrected now, I see that the "normal speed clay" had to do something with it.
Though I have more things to report and I think they might be present in b30.
I was using older saves so I cannot be sure if they're not corrupted but you can surely check.
1) One is somehow incorrect behaviour after hiring sparring partner.
When I tried to train the players practicing with each other in coach center everything was OK.
After I hired sparring partner I am able to practice with him but if I choose any of the other players I get completely different players selected.
Some have even crazy stats like rank 0, 65535 points and 255 tournaments played.
2) I was able to get in the state where all four players are playing FedCup.
Three of them are in some country but the fourth is in country Fed Cup.
Obviously she has incorrect options as to which players she could practice with but maybe you'll find there's more than that.
And again these two problems might be related...
I'll send you the savegames where you can see both problems and I was able to reproduce (1) also from the w51 savegame which I already sent you.
When trying to reproduce (2) in b30 the game crashed (I'll send the System.Log also).
But I think once I got through and it looked the same. And the crashes occur exactly when trying to send the player to country Fed Cup.