Unable to Drag & Drop Indicator

 
I downloaded Keltner Channel.mq4 from this board.  I copied it to my Experts\Indicators folder, and I see it in the Navigator.  However, when I drag it to my screen nothing happens (I can't attach it).  What am I doing wrong?
 
Indicator must be compiled into ex4-file. Open it with MetaEditor, try to compile and see compiler error messages
 
stringo:
Indicator must be compiled into ex4-file. Open it with MetaEditor, try to compile and see compiler error messages
When I try to compile, I get a message saying "could not open compiler". I've tried it on two different platforms and rebooted. Any ideas?
 
Probably there is antivirus McAfee on your computer. This antivirus deleted the MetaLang.exe.
Reason: