I enabled fingerprinting in Picard and I chose AcoustID fingerprinting provider before I actually installed fpcalc. Picard:

1) saved the preference without beeping a thing
2) allowed me to "scan" the files
3) pretended successful end of scan
4) allowed me to "Submit" the IDs - that eventually failed with error 299

IMO the check for actual fpcalc availability (presence & executability) in the system should be at point 1 or 2.