[Mobhack]

Usually, nothing at all noticeable. I have had many WW2 long campaigns go on through several code and OOB updates.

Occasionally though there may be a unit that has a hiccup - maybe the icon goes invisible, or changed to the "unknown" icon etc. But that only happened to me when I had been using an OB with own mods, once.

The cure for that was to simply change the unit to something else at the next upgrade point.

Secure PBEM games however, cannot be played through an OOB upgrade.

Cheers
Andy