Slitherine

Only had this once in one battle against rebels - there appeared to be three of every rebel unit that the campaign map had shown in a battle to retake a province from rebels. During deployment i could see all enemy units, some appearing as they would during a battle normally (but not as they should look in deployment as just the faction symbol), others (the ones that turned out to be illusions) appearing as the unit with the faction symbol over its unit picture.

When the battle started i found out i couldn't target some units and could move into the hexes they were in (the 'ghost'/illusory/bug units), while others were 'real' and fought as normal.

Half way through the battle the game crashed entirely.

Would emphasise this seems to be a very rare bug - and after restarting the game and reloading it was gone and worked fine