Problems with audio - e.g. We couldn't download your audio, please check the URL and try again

If you are receiving an error error "We couldn't download your audio, please check the URL and try again" please make sure of the following best practices: 

• Don't use any weird characters such as -%^#@+(), etc
• Don't add too many spaces between words.
• Don't just copy/paste your script from word or websites directly to the editor.
• Try to preview the same script with a few other voices