Metal Gear Solid: Peace Walker

[Retroboy]

am i been stupid but im stuck, im at a mission which i need c4, ive tried getting RnD to make them but nothing, i did a few missions to see if it would work but im stuck.

i started a new game but still noticed that instead of taking me to the next mission, it takes me back to mother base and has random crashes like before when loading next mission, but not as often as the older build.