ERROR for code!

I recently made this grappling hook and I really wanna fix it as soon as possible!

Whenever I die from a drop with the crossbow equipped sometimes I crash with this error!

[Grappling hook V2] lua/entities/trace2/cl_init.lua:66: attempt to index local 'attachment' (a nil value)
1. unknown - lua/entities/trace2/cl_init.lua:66

In the code line 66 (Including surronding lines!)

local vm = Owner:GetViewModel()
if (!vm || vm == NULL) then return end
local attachment = vm:GetAttachment( 1 )
StartPos = attachment.Pos (THIS IS LINE 66!)

else

local vm = Owner:GetActiveWeapon()
if (!vm || vm == NULL) then return end
local attachment = vm:GetAttachment( 1 )
StartPos = attachment and attachment.Pos

 

I don't really deal with this sort of stuff so I may be wrong, but try something like this.

http://maurits.tv/data/garrysmod/wiki/wiki.garrysmod.com/indexaf14.html

 

I am new to coding, that is something I really couldn't do.

 

I nearly lost this, if someone could still help me with it?

 

Your problem is the "vm:GetAttachment( 1 )". When you die with your crossbow out, I believe it returns no attachment, and therefore a nil value; Causing the crash.

 

How do I fix it?