Creare Videogiochi - Game Developer

oltre ciò chiesto ultimamente il gioco quando vado a testare mi dà segnali di errore tipo questo :

___________________________________________
############################################################################################
ERROR in
action number 1
of <Unknown Event>
for object wall:

ERROR: The polygon shape for fixture 6 is concave or ordered anti-clockwise
############################################################################################

e questo vale per tutti gli objects .
Cosa posso fare ?
Potete rispondere ad entrambe le domande ? Grazie in anticipo !