Q: I launched fmit executable, but it blocks immediatly, without errors.
A: Stop other audio programs like jackd or any program wich could keep the capture device jealously.
(it should never append in last releases)

Q: Sound is incoming into FMIT, the Note Stability is grey but nothing else happen
A: 1) Try to increase the input volume by changing your mixer configuration. 2) Try to decrease the Volume treshold value under "Configuration/Sound Analysis/Algorithm" (move slider to the left)

Q: FMIT get no sound at all, nothing happens
Q: FMIT get sound, but the arrow shakes in all directions
A: Maybe the input channel is not correctly selected in your mixer settings. For example, the analog input is selected instead of the microphone. Try to change the recording channel.

(I know this is very please-check-the-plug advises ... though most questions I receive are about this kind of issues)