ILLEGAL: n e8-f6 on turn 4:
There was no n on e8. The piece on e8 is a q.
Go back with your browser's BACK button, reload the page, and try again.
For diagnostic purposes, here is the full movelist:
1. P g2-g4 
1... p e7-e5 
2. P h2-h4 
2... a f8-e6 
3. P g4-g5 
3... p f7-f6 
4. P g5-f6 
4... n e8-f6 
5. P b2-b3 
5... p d7-d5 
6. A g1-f3 
6... p c7-c5 
7. A f3-g5 
7... p d5-d4 
8. P d2-d3 
8... p e5-e4 
9. P h4-h5 
9... p e4-e3 
10. A g5-e6 
10... s d8-e6 
11. P f2-e3 
11... p d4-e3 
12. N d1-e3 
12... c c8-e7 
13. N e3-f5 
13... c e7-d5 
14. P h5-h6 
14... p g7-g6 
15. DH h1-d5 
15... n f6-d5 
16. N f5-g7 
16... s e6-g2 
17. K e1-d1 
17... n d5-e3 
18. C f1-e3 
18... s g2-e3 
19. Q c1-e3 
19... q b8-h2 
20. S b1-c3 
20... q h2-h1 
21. S c3-g1 
21... r a8-f8 
22. K d1-d2 
22... dh g8-d5 
23. S g1-h1 //g1-g2-h1 or g1-h2-h1
23... resign
In case there is a bug in the code, the settings file can be edited at /play/pbm/play.php?game=Cetran+Chess+2&settings=asymmetric&submit=Edit