Oh one Thing:
I made this function too:
void MyCharacter::SetWeaponReference(AWeaponBase *WeaponToSet)
{
WeaponReference = WeaponToSet;
}
And then i call fire:
void MyCharacter::FireMulticast_Implementation()
{
WeaponReference->Fire();
}
This Weapon Reference is set up in Blueprint. I call the function and set the current weapon blueprint as reference.