R – sIFR 3 r4.36 has problem with Flash 8

I cannot export any font with Flash 8 using sIFR 3 r4.36. Flash 8 always shows the following error message. Any idea why?

** Error ** Scene=Scene 1, layer=code, frame=1:Line 19: The class or interface 'sIFR' could not be loaded.
     import Options

Total ActionScript Errors: 1     Reported Errors: 1