i have scope 4.5 project, 6dsp in the registry i can see Flexor (though it does not say 1.5) and the non-adern/scope modulars do work.
and there is also: cant find midi to faktor +/-
i think you didnt install flexor itself. its not enough using the patch pack. in the flexor release inside the DSP folder there is the ADXFLX file (same as obxflx) put it into Scope/App/Dsp