Unable to Attack Anyone...

Hello - I seem to have an interesting problem.  I am playing a randomly generated map - and I have gotten so far in the game (really enjoying this one) - and I had the game crash.  When I go back into it - I cannot attack anyone on the map... 

When I move next to a an enemy unit - and I try to attack (I see the crossed swords when I move the mouse over them) - nothing happens... 

Any thoughts as to what is happening? 

Bradley MacDonald