Assembly problems

[VirtualGamer]

I'm doing the first mission, I've repaired and painted, but I can't assembly tracks, is it a glitch? Pressing 1 does not work

[Spaghetti Salmon]

Try pointing yourself at the tank and pressing 'R' to bring up the radial menu. On the lower right of the circle, you’ll see a button with a '+" to choose to assemble parts or '-' to disassemble. You need the '+' right now. Then, as you move around and point your crosshairs at various missing parts, you should see them appear in a ghostly form. Hold the right mouse button to put such parts in place. The parts will disappear again if you don’t add whatever fasteners are required straight away, e.g. bolts or track pins. You might need to zoom in a little (mouse wheel while assembling) to see all the fasteners.

Finally, note that if you don’t have the correct part, you’ll see a message to this effect.