Something very fishy is going on. I discovered that what GAME code prints is hidden in the header of the preset page, so I could see it by looking at the Page Source. (A bit inconvenient, as it is buried in an insane number of empty <P> tags, but I managed.)
I experimented a bit in Play mode, and the fastest way to reproduce the disappearence was 1. j3-j5 i10-i8 2. j5-j6 i18-i7 3. Nk2-j4 and i7 would disappear. In particular, the problem occurred when a Pawn was moved a single step to attack another Pawn; that Pawn would then disappear.
So I put statements in the GAME code to see what move was offered to GC for playing. This was simply "N k2-j4", no instructions to remove anything else. So I printed the board just before that move would be executed. The Pawn was already gone. So I tried printing the board earlier in the process of verifying the legality of the move, to see at which point the Pawn would disappear. But after that the Pawn on i7 did not disappear anymore!
That was weird. Printing something should not alter what the code does to the board. I commented out that extra printr statement, and later removed it alltogether, to go back to the situation where I last saw the problem, only printing the board just before the move was made. The Pawn did not disappear anymore. So I removed all print statements I had added for debugging: the Pawn stays. I played to the game position: also there no Pawns disappear.
So it seems the problem has cured itself, without making any changes to the preset. Please try again to make a move in the game, to see if you have the same experience.
Something very fishy is going on. I discovered that what GAME code prints is hidden in the header of the preset page, so I could see it by looking at the Page Source. (A bit inconvenient, as it is buried in an insane number of empty <P> tags, but I managed.)
I experimented a bit in Play mode, and the fastest way to reproduce the disappearence was 1. j3-j5 i10-i8 2. j5-j6 i18-i7 3. Nk2-j4 and i7 would disappear. In particular, the problem occurred when a Pawn was moved a single step to attack another Pawn; that Pawn would then disappear.
So I put statements in the GAME code to see what move was offered to GC for playing. This was simply "N k2-j4", no instructions to remove anything else. So I printed the board just before that move would be executed. The Pawn was already gone. So I tried printing the board earlier in the process of verifying the legality of the move, to see at which point the Pawn would disappear. But after that the Pawn on i7 did not disappear anymore!
That was weird. Printing something should not alter what the code does to the board. I commented out that extra printr statement, and later removed it alltogether, to go back to the situation where I last saw the problem, only printing the board just before the move was made. The Pawn did not disappear anymore. So I removed all print statements I had added for debugging: the Pawn stays. I played to the game position: also there no Pawns disappear.
So it seems the problem has cured itself, without making any changes to the preset. Please try again to make a move in the game, to see if you have the same experience.