Hi if i may add,
when spying some one and fails on one province then the "retreat all" button doesn't work.. It says something like "you do not have infiltrated spies anymore".. when this is not true, only failed in 1 province but they are in the rest and we need to call them back 1 by 1, or wait till those spies who failed return home then the "retreat all" button works again.
I think that is minor mistake but it is annoying to recall 1 by 1..
cheers