Why is it that sometimes I can't rest my party, or save the game?

if you just fought and havent let that awful fight music quit playing you cant rest, or if any combat spells are still active, ie; tangle, berkserk etc. you cannot sleep or save as it counts you as still being in battle.

it may be that there is still a spell in action that stops you from saving, party may be too scattered to rest or save or there may still be combat somewhere.

Also sometimes there is something directly involved with a quest going on such as two guys fighting over a girl or some Viconia person about to get scorched; stuff like that. Also sometimes the game just screws up (at least mine does anyway). But all you have to do is leave the area and you should eb able to save/rest again. Lastly if there are any creatures nearby that aren't currently attacking still could be considered enemies. It really depends on what it says when you attempt to rest: during combat, not at this time, enemies still around, not in control of all characters