I'm flying in Poland (for the Germans), and trying to give the Polish their bombers (they only come with fighters in the campaign), but whenever I try to add a Polish squadron, I get an error:

"New0 was not identified in squadids.dcg. Please correct the file before continuing."

It won't let me switch from New to another existing squadron in UnitName, such as one of the other extant Polish squadrons, it just throws the same error. Am I missing something here?

Also out of no where it suddenly transferred my campaign to France, wtf? It had been like 2 days. I tried to restore backup and it still says France 1940. And yeah the backup erased all of my progress, so that sucks.

Sorry for the late answer but it looks like I must have introduced a bug at some point that's messed up the save for selecting a new squadron name.  I'll fix that.

Unfortunately for your campaign, it messed up the data files and that pushed it on to France.