The new version (v.1.02.19) has a new chess puzzle in chapter 4. How do you solve it?

No it isn't. The lockbox has only pairs of combinations now (i.e. 6/2 on position 1, G/C on position 2, 4/8 pos 3, G/C pos 4, 7/3 pos 5, B/F pos 6, 1/5 pos 7, B/F pos 8. Your answer is kinda void, not really helpful.

Not sure if you are referring to the same box. The box next to the chess board has 8 dials, these alternate as letters then numbers then letters etc.
The ideas is that the solution is a set of 4 coordinates on the board, A1, B2 etc. This would make an 8 digit combination made up from the letters and numbers. The full solution is shown in the guide.

Y si es un error me dice que cambio el puzzle