Ok ... there is no such problem ... flying knives need to be obtained from agile soldiers ... and then you can adjust the weapon selector and take out other things again. ...

Open my document/Assassin's Creed Four Black Flags/assassin4.bin.

Found under the column [default binding of keyboard and mouse 2].

PadUp=- 1

PadRight=- 1

PadDown=- 1

PadLeft=- 1

Amend as follows:

PadUp=2 1

PadRight=36

Paddock =35

PadLeft=34

After entering the game, use buttons G, Y, H and J to bring up the weapon turntable for personal testing.