Code Editing the Holy Hand Grenade?

[Toblerone]

Hi there!

I'm trying to compile a weapon but it does not work, it gives me this error:

Can't find file 'Hallelujah.WAV' for import
Can't find file 'UnholyBlowup.WAV' for import

I have this hierarchy: ...Killing Floor/System/HolyHandGrenade/Classes
...Killing Floor/System/HolyHandGrenade/Sounds
And I have these sounds THERE in sounds folder, why does it give me this error?

Here I leave you the full error text message:

----------------------HolyHandGrenade - Release-----------------------
Analyzing...
Parsing SlotCard
Parsing HolyGrenadeCard
Parsing BlackHoleFX
Parsing HHGExplosion
Parsing HHGTrail
Parsing HHFragAttachment
Parsing UHHFragAttachment
Parsing HolyHandGrenade
Parsing UnHolyHandGrenade
Parsing HGrenadeMessage
Parsing HGrenade
Can't find file 'Hallelujah.WAV' for import
F:\1.Krasy\KillingFloor\HolyHandGrenade\Classes\HGrenade.uc(3) : ExecWarning, Failed factoring: NEW SOUND FILE=Hallelujah.WAV PACKAGE=HolyHandGrenade.FX NAME=Hallelujah
Parsing UHGrenade
Can't find file 'UnholyBlowup.WAV' for import
F:\1.Krasy\KillingFloor\HolyHandGrenade\Classes\UHGrenade.uc(3) : ExecWarning, Failed factoring: NEW SOUND FILE=UnholyBlowup.WAV PACKAGE=HolyHandGrenade.FX NAME=UnholyBlowup
Parsing BlackHoleProj
Parsing HHGFire
Parsing UHHGFire
Compiling SlotCard
Compiling HolyGrenadeCard
F:\1.Krasy\KillingFloor\HolyHandGrenade\Classes\HolyGrenadeCard.uc(30) : Error, Call to 'ReceiveLocalizedMessage': type mismatch in parameter 1
Compile aborted due to errors.
Failure - 1 error(s), 2 warning(s)

F:\1.Krasy\KillingFloor\System>pause
Press any key to continue . . .

What do these errors mean? Could anyone help me, please? I'm a newbie and I'm not very familiar with Unreal Script, but I do have some knowledge of Java and C++.
Btw, I have asked the author(Marco) for permission to edit his code, he allowed me to do so.