The Native Browser Previews Library tends to fail on Windows when it exceeds the 255 character limit.
It seems that Native Access does not catch that error and "Previews" remains indefinitely as "installing" in the Download Queue.
Please carry out the following workaround:
Quit Native Access and restart your computer
Run the Previews installer directly via the following link, and make sure to select a short installation path: Previews installer
Restart Native Access