If you install N.I.N.A. in x64 architecture your ASCOM drivers will also need to be provided as x64. Unfortunately some manufacturer still do not provide x64 drivers. In case you are having trouble connecting to your equipment, please switch to the x86 version of N.I.N.A. or ask your manufacturer for x64 drivers.
This is the latest stable released version of N.I.N.A.
The version did undergo a fair amount of testing and is stable to use for your imaging runs.