There may be several reasons for this. The first thing we suggest trying is check that your browser is updated. Hint: Firefox and Chrome are the best browsers in which to experience Chordify. Next, you should try disabling all addons in your browser. Some addons prevent Chordify from working properly; there are known issues with "HTTPS everywhere" and "Norton Identity Protection".
If that doesn't help, please contact us, specifying which device, operating system and browser you are using, including as much detail as you can and sending a screenshot of the problem if possible.