Attempt to index local 'Unit' (a nil value)

[chris999]

Resolved - downloaded a new repack

[chris999]

Resolved - downloaded a new repack

[Facerolling]

It is saying you have errors in lines 15 and 19.

I think the error on line 15 is that you have a space between the comma and Unit. Try this instead:

Unit:CastSpellOnTarget(63355,Unit:GetMainTank())

The error in line 19 is that there should be no brackets around Unit:GetHealthPct() <= 50, so the correct line would be:

if Unit:GetHealthPct() <= 50 then

[chris999]

Thankyou for the reply, shows that perhaps there is hope :P
Unfortunately, I made those two renditions yet still sufferred from the same error. :\
Should I try a different repack? I currently have Shadow's Repack 3.3.2 V2.1.

EDIT: RESOLVED