Using findEmptyPosition on some locations will simply return a position that isn't valid for spawning/positioning the specified unit type.
Example: Rocks on cliff east of the road going south out of Agia Marina.
Basically, the the valid check for the positions returned needs to be more strict in order to make findEmptyPosition safe to use.
Put this code in a soldier's init line:
player setPos ([2793.41,5884.82,0] findEmptyPosition [0, 1, typeOf this]); onMapSingleClick "player setPos (_pos findEmptyPosition [0, 1, typeOf player]); hint str _pos; diag_log _pos;";
I am having similar issues with just the map editor.
See: http://feedback.arma3.com/view.php?id=2563
Ironically, somebody suggested using findEmptyPosition to counter this. :s
Just noticed http://feedback.arma3.com/view.php?id=4029 was closed due to lack of activity, though the issues are related.
Unless I missed something, this wasn't fixed yet, and it's quite critical for some scripts/missions.
I ran into this too, rocks seem to be the main problem for me. As long as they're big enough for the unit to fit inside without touching the actual mesh then the command thinks it's empty.
Not just rocks, buildings too. For example ghost hotel will repeatedly create this issue.
This is still an issue (often game-breaking and requires many nasty workarounds).
It would be very helpful if this command worked reliably.