Paul P Bugai : "Fix each preset manually this is an extremal variant. Convert all flacs it is not difficult of course, but (if i understand correctly) need also *.sfz fixed. And this process is not so easy to automate." With grepWin, it takes just a few seconds. Just tell it to replace all occurances of ".flac" with ".wav" and it will fix everything in one shot. I'd make a copy of your folders before playing with them.
excellent suggestion I will try this