Compiling PortableFirefox.nsi

Hi when I try to compile the PortableFirefox.nsi, I get the following error.
IfFileExists: "$PROGRAMDIRECTORY\$PROGRAMEXECUTABLE" ? FoundProgramEXE :
MessageBox: 48: "$PROGRAMEXECUTABLE was not found. Please check your configuration"
Abort: ""
StrCmp "$ALLOWMULTIPLEINSTANCES" "true" equal=ProfileWork, nonequal=
Invalid command: FindProcDLL::FindProc
Error in script "E:\Software\Portable Software\PortableFirefox\PortableFirefoxCode\PortableFirefox.nsi" on line 185 -- aborting creation process

I've been through everything i can, still havent fixed it. Please can someone help?