This is a small summary I learnt about this game. Winters games work ok. Javelin toss fails in Summer games. In order to fix it, download anywhere another Summer games and replace your SUMMER folder content with the new one.

However, with non-gog summer game, I've noticed high DOSBox cpu cycles crashes the game. I've tested few hours with cpu_cycles = 2000 and it work fine. If it still crashes in the main menu is because it detects a false "debug mode". It shouldn't happen with 2000 cycles, but if it would happen load the game and go to game setup instead train or tournament.

So, summary to fix problems, use another Summer Challenge game and set cpu_cycles to 2000