Well I'm not sure exactly why as I would think the UBound Redim Preserve would handle it but the folder path appears to be an issue for me when testing with %USERPROFILE%
I get: "ERROR : Error in expression: this type of array not supported in expressions.!"


Doing an If check seems to fix it. I'm sure Jooel or Bryce may be able to determine why but I don't have anymore time to work on it.

Code:
If $Path
    $PathSizes[AScan($Paths,$Path)] = $PathSizes[AScan($Paths,$Path)] + $File.Size
EndIf