!! Warning: this hanjie has 36 solutions !!
To find the good solution, you have to know the last black cells indicate the squares used by a chess knight. In this grid, the knight starts on the top left black square. He never takes the same square twice.
Thus, you'll need to combine the rules of hanjie with the rules of knight's moves.
The trick I give in the number 3 can be usefull.
Here is a reminder of kight's moves : https://www.memory-improvement-tips.com/images/knightmoves.png

Difficulty : ****

Tested, logical (with the statement).
Don't require any specific method, but a horse to ride.
Good blackenage and good equitation.