thank you so much scook for your answer but, it's my fault, because I didn't explain well, the Spitfire plug-ins appear in the Plug-in Manager (see photo) but not in the Layout, I added (add plug in) the Spitfire in the Layout in different positions (Sampler, Synth, u-he, uncategorized) and I called this new Layout: aa but to no avail
Of course I reinstalled the Spitfires several times but since Cakewalk "sees" them I don't think it's a problem Spitfire
Ps. I have been using cakewalk since 1996, it is a splendid and today even free program, underestimated by many for ignorance
Ps, I am 71 years old and therefore your patience is needed !! I am a composer of music for films and TV
many thanks again