Welcome!
I'll be glad to offer help. As a general rule, you also need to change "Field Ownership", or else you may find that the bad guys own the takeoff field and will fire on you as you describe. Since my missions are always based on combat between Knights and Bishops only (I never use Rooks), here's a general rule:
If you are taking off as a Bishop and the ground gunners are firing at you, change the ownership of that field to Knight.
Conversely (of course), if you are taking off as a Knight and the ground gunners are firing at you, change the ownership of that field to Bishop.
This is done from the clipboard "Options", under "Arena Settings", I think.... The interface is fairly intuitive and you shouldn't find it difficult. Once this change is done, it will be permanently remembered until explicitly changed.
I thought I had made that clear in the various mission download pages, but I observe that I forgot to do so for PacMix01. Sorry about that. I'll enhance it for the benefit of others. Thanks for bringing this to my attention!
