Problem seems to also occur when your opponent is using platoons that have replacements.

You get them to those platoons that have taken casualities, and they come at night turns. It reads on their experience "Trained" or "Well Trained". You can bypass those errors if you use other infantry platoons. This seems not to effect tank platoons at all.

<t> It has something to do with those platoons that receive replacement soldiers. I get these same errors, everytime I use those platoons. It comes when I'm placing those units and I select more than one unit at a time. Or if I don't select more than one, and continue with battle the error message ...