Program crashing at random points

[Alaanor]

I've been beating myself up over this, it's so frustrating.

I'm using SFML but it should matter, anyway.

What I'm trying to do is have a vector of enemies, and when the player kills one, a boolean is set to false, then, I use a pred function with a remove_if (in a while loop), and if that boolean is false, erase the element from the vector. Then, if enemies is empty, then create 5 enemies and push_back them into the vector.

I can't paste my entire code on here (500 lines so far), but here are the relevant parts. (So, still compilable if you put it in a standard program)

  while (window.isOpen()) {
			if (spawned == false) {
				
				for (int i = 0; i < 5; i++) {
					Enemy enemyNew(enemy);
					enemyNew.setPosition(sf::Vector2f(100 + (i * 120), 100));
					enemies.push_back(enemyNew);
				};

				spawned = true;
			};

			if (enemies.empty()) {
				spawned = false;
			};

			for (int i = enemies.size() - 1; i >= 0; i--) {
					enemies.at(i).update(Time2, playerSprite, movement, current, enemies);
					enemies.at(i).moveToPlayer(playerSprite, 100, Time2);
					enemies.at(i).draw(window);
			};

			enemies.erase(std::remove_if(enemies.begin(), enemies.end(), predEnemy), enemies.end());
  }

It returns vector subscript out of range , but doesn't tell me where in my program?!?!

As soon as I kill the enemy, and the boolean is set to false, (which then the remove_if fires), it happens, but if I wait a little, say, 4 seconds, and then kill the enemy it works, but then crashes the next few times...

Any help is appreciated.

[mbozzi]

It returns vector subscript out of range

Since there's no use of the subscript operator in the code you posted, that problem is not here.
Use a debugger to check the call stack when your program crashes.