How to start game in mission editor?
 

I don't understand
what should I do to play my mission that I made it in mission editor?
(for example with two subs hunting for each other)

sorry on my bad english :)

Once you save your game in the editor, it should be playable in the single player or multiplayer menus. If it does not appear there, find the saved game file and move it into the Scenario directory.

It wan't
when I try to save mission file-save mission as
it says 'You must specify a tactic for this object'
although I selecded a tactic
and than I don't know what to do

You must both select and place a tactic. For example, you first select a 'Random Box' tactic in the object properties panel, and then define where in the map you want the box to be.

Yeah, if you can't get out of the editor without warnings, you aren't going to be able to save the mission or any changes, I believe.

Thanks zma,
it works very well :P