Thanks.
The game crashes...damn.

It just doesn't load.
What I did:
Searched for players with team 44 and 45. changed this to 32. Same for cash team. --> previous rookies & sophomores are gone.
Next step:
I looked for e.g. Scola. -> edit -> copy.
Scrolled down, new line. Pasted the player.
Assigned a new ID to him.
Changed his team to 44, cash team to 44.
Repeated these steps for all players of the rookies and sophomores.
Gave them unique roster positions...0 = starting center, 1 = PF, 2 = SF, 3 = SG 4 = PG... 5-8 = on bench.
Then I opened the appearance. Copied all players...and matched their IDs.
e.g. M. Conley has 2438...and he also has the ID in the appearance.dbf.
Why the crash? Did I forget something?