FairUse4WM 1.3 error: Failure - Unable to identify RC4 and AES internal keys

I have downloaded FairUse4WM version 1.3, and whenever I try to recover a key, this pops up:

"Extraction in progress on "Indiv01.key" 11.0.6000.6324 -- Please wait.
Phase 0 : Blocks: 1340 Large 0 Small, Errors: 0,0 Candidates: 5,3,2
Failure - Unable to identify RC4 and AES internal keys."

I press OK, and then this comes up:

"FairUse4WM will use a WM-Installed DLL to determine system specific information.
"DrmClien.DLL" has version 10.0.0.3802"

I have no idea what to do. Please help.