Javascript errors

I’m not sure why but randomly there is posts where the button is not being displayed, but it works fine on others. The javascript error is always on text-to-audio-button.min.js in a line that says:

for (var o = window.TTS.contents, r = window.TTS.settings, a = Object.keys(o), c = function() {

and error message displayed by browser is:

Uncaught TypeError: Cannot read properties of undefined (reading ‘contents’)

I hope that you can solve this ASAP.