My particle effects and the line renderer are invisible

Im making a 2d platformer with the brackeys tutorials. I added a bullet trail to a gun and particles to the respawn. Both work but they are only visible in the scene window and only if there is no other background/foreground sprite over the particles or the line renderer. I googled this issue and tried a lot with z values and layers but i cant fix it (btw im a beginner so its possible that i forgot something stupid or whatever). I even tried to fix it with a script from a youtube comment:

// Use this for initialization
void Start () {
	LineRenderer line = GetComponent <LineRenderer> ();
	line.sortingLayerName = "foreground";
	
}

but it doesnt help. I hope someone can help me im stuck and i cant go on withouzt fixing this.
(If I change the scene view into 3d i can see the both but only in a perfect 90 degrees angle from left or right or from top/bottom but not if i look from the front, if you know what i mean)
thanks for helping me :slight_smile:

Maybe my description is a bit unclear with “they are only visible in the scene window and only if there is no other background/foreground sprite over the particles or the line renderer” i mean that i only see them if they are over the standard background and not if any of my sprites are involved. And of course in 3d view from side but i already mentioned that.